VW A1 A2, A3, A4: Radiator fan(s) quick check.
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- čas přidán 23. 08. 2024
- Thomas
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Your advice was very useful to narrow down the issue. Figured out that the connector, which is on top of the battery compartment, had melted resulting in no power supply to the fans. I have by passed the connector and introduced a fuse. Now the fans and AC are working. Thanks a lot for your support.
Thank you for watching!
I cannot tell you how much you just helped me. When you shared this the light bulb went on in my head thank you for helping me make a connection.
Let me know if you run into any issues.
I like simple diagnostics and your statement about not being able to troubleshoot a car with a keyboard. Classic.
Not all problems have a silver bullet answer... a little investigating can make a big difference. Too many people just want to know the answer, instead of learning to look for themselves.
Just helped me isolate the problem in seconds! My switch appears to be bad - when I bridge the two connections the fans kick on. Thanks so much for taking the time to make this!
Make sure that you have coolant circulation... if the switch does not get warm, it can't turn the fans on. Year, make, model, engine? Do you have heat inside the car?
@@EXOVCDS 1998 Jetta GLS 2.0, the heat works great.
Did the "fans not working" happen after any recent work on the car or you just noticed that the fans were not coming on anymore? If it also runs hot while you are cruising at a steady speed, it's probably a thermostat issue.
@@EXOVCDS Fans didn't work when I bought the car. It does run hot while cruising steady, and after further investigation the upper rad hose is hot while the lower hose is cold. I believe this indicates a stuck closed thermostat? If it didn't overheat when cruising, would that rule out a stuck closed thermostat because the coolant could cycle through the radiator and be cooled sufficiently by highway air alone?
Yes... if it does not run hot / overheat while driving, then the thermostat is OK.
If you let the engine idle to the point where the needle starts to move past the middle... bypass the radiator fan switch (like in the video). If the temperature needle starts to come down, then the sensor is bad. If the needle does not come down, then it could still be a thermostat issue (not opening fully).... raising the engine rpm will circulate more coolant through the partially open thermostat and temps should then come down as long as the fans are running.
Very odd. I had a problem with my fan not turning on. I unpluged the connection, tested low speed and it worked. Plugged it back, and now my fan problem is gone. Ice cold ac all the time now! I guess playing with the connection solved it. Thank You!
Yeah... bad connection / corrosion can cause issues. Simply moving connectors / wires can sometimes get things working again. A closer look / inspection should still be done (to find the exact cause, so it won't happen again).
Hi Thomas, always great info. Here's my problem (yup, my daughter's Beetle, 2000 TDi). Her fans don't come on when they should. I did this bypass you showed and they worked fine. I replaced the FCM (tested the old one and the new one on my Jetta to make sure they were dead/working, so I know the part needed to be replaced and was with a good one) and replaced the temperature sensor switch as well. Checked and replaced the fuse on top of the battery. I checked the wires leading into the FCM as well, can't see any wear or breaks. Stumped. Help!
In my 09 the cooling fan wasn't turning on and the big radiator fan only worked in high speed, then I checked the fuse and it was good so I put another one just in case then both fans worked fine for a day, now it's back to just high speed ,I checked the fuse and it's good.
Your fans are controlled differently. The fans are controlled by the ECM. The ecm sends a signal to the large radiator fan (fan control module is part of large fan) which then turns on the large fan & small fan. If the fan module receives a signal from the ECM, but the small fan is not working, then the fan module or the small fan is bad. Use a multimeter to check ecm control of the fan module and the small fan for voltage from the fan control module.
czcams.com/video/oqdv4cm86Ns/video.html
Hello, I have a 2004 jetta gli 1.8t low speed fan not turning on and car over heats in traffic on the highway temperature stays half way. When ac is turned on big fan works replaced the 30amp fuse and low speed fan and after fans when the car is turned off not working any idea?
Follow the steps and let me know what happens.
Great video, thank you for sharing, I have just the opposite, my fans run as soon as I start the engine, my car is a 2003 Audi A3 1.9 tdi. I might take the fuse out during the winter time.
Malc Tulloch Simple enough to check why. If your radiator has a fan switch, unplug it. Are the fans still on? If it does not have a radiator fan switch, look for a sensor in the lower radiator hose. When AC is selected, the fans will always be on. The fan module could be stuck internally. Let me know what you find.
Thank you so much for your reply, I didn't know about the A/C keeping the fans on, I have only just bought the car & have a lot to learn. Thanks again!!!
I took the right hand green fuse out & started the engine, I have played with the air-con still not too sure about it though. anyway, I put the fuse back in & the fans don't run while the engine is cold, as you said, it's affected by the air-con. Thank you very much for your videos, you're a gent!!
@@EXOVCDS your videos are tremendously appreciated. They empower average people who are not auto mechanics to quickly troubleshoot and repair simple issues that could be serious if not addressed, and help avoid hundreds if not thousands of dollars in parts and labor costs at a repair shop. Thank you.
@@RedondoBeach2 thank you for watching!
New beetle 1.8t. Pulled the triangle plug and jumped the pins. Both the low and high speed functions work. I applied direct power to the fans and both work on low and high speed. My AC still won't turn on and my fans do not work on low speed at all. High speed function works fine. I am at a lost on whats causing the low speed fan not to work/AC not to turn on. I have replaced the FCM twice now with no change.
What year? So that I can look at a wiring diagram.
@@EXOVCDS 2000, APH engine code
If low speed fan does not come on, but comes on when manually bridged, then the rad fan switch is bad or the thermostat is stuck closed.
If the engine does not overheat then the thermostat is ok.
Is fuse 5 OK? 7.5A
AC not coming on could also be due to low charge.
@EXOVCDS just checked fuse 5 seemed ok but replaced it anyway just to be sure. It didnt seem to change anything. Could the rad fan switch cause the fans not to work causing the AC compressor not to kick on? Assuming it's charged enough to turn on?
No. Rad fan switch is separate / should function separate from AC. Fan module turns on fans when AC is selected... providing charge is ok.
Thank you very much Sir. For sharing your videos I have Volkswagen beetle the fun start not working and my car temperature light start on.
If you can't find the problem, let me know.
I watched the video, and looks like my fan connector, but as i watched the video he described all of what happened , small fan stopped working first, then the large one stayed on all the time, then a/c stopped blowing cool a few days ago, now fans wont come on and overheating in traffic. I'm thinking replace both fans?
Yes, probably both fans have quit... especially when AC is used a lot. The fans will always run when AC is on. You might still want to make sure that the fan module (large fan) has good power & ground at the main harness plug.
My 2004 passat has a control module under the fender in front of the driver side wheel. It gets super hot, my Radiator fan doesn’t come on. Bought a new fan and returned it because it didn’t work. Ordered a new control module. Hoping that will fix the issue. All fuses and relays are good.
2 electric fans or 1 electric + belt driven fan? Which engine? Overheating or no overheating? Idle only or also when driving?
Interesting about the fuze too.
It's always overlooked... and the connector at the fuse box too (I forgot to mention that)!
My problem is that the screwdriver gets lit but when i connect the any of the two pins the fans dont start
Year, make, model, engine?
I don't know what a lit screwdriver is.
Thanks bro but on table fan connection please
Nice quick tips on how to troubleshoot the fans and very clear in your explanations...
Thanks... but I always forget to mention stuff! =(
I have a 01273 fresh air blower code and I believe the small fan is not working. But I would like to test it to be sure.
The video deals with radiator fans... your code refers to interior fan(s):
wiki.ross-tech.com/wiki/index.php/01273
Great video step by step explanation.
Thank you for watching!
I am writing in the hope that you can help me with the issue i have with my car. Car is Passat B6, 1.4 Tsi. The problem is next: When the AC is on, both fans are spinning at low speed and everything seems fine and quiet. But when the AC is off, main (bigger) fan kicks in from time to time, but only at high speed and only for a couple of seconds and then turns off. Also, when i turn off the engine and the AC was on during driving, both fans runs normally and after 2-3 minutes shuts off. But if the AC was off during driving, as soon as i turn off the engine, only bigger fan starts spinning, again at a full speed and sounds like a jumbo jet. That lasts for a couple of seconds and then turns off. Immediately after that, main fan starts spinning again at full speed, again for a couple of seconds and again turns off quickly. Basically, it runs on/off at full speed for a very short period of time and after couple of that ,,on/off sessions'', smaller fan kicks in and from that moment both fans runs normally and shuts off after couple of minutes. In short, it seems to me that the main fan is not able to work at low speed alone, without a smaller fan working too. Without AC, it runs only on high speed for 5 seconds and turns off. And that scheme repeats over and over. What could be the problem here? I don't know what to look for.
I would start with a full system scan, to see if any of the modules have cooling fan codes. I would then look at a wiring diagram, to see if there are other fuses that power the fans when AC is off. It might end up being a fuse problem or a fan control module problem. I can't be sure at this point, because I have not looked at a wiring diagram.
@@EXOVCDS Thank you very much for the response. I've checked today all the fuses (fuse by fuse) with multimeter and everything seems ok. I have also scanned all modules with Vcds and i've got two faults:
-Control Module 2 for cooling Fan P1948 - Output short circuit - Intermitent;
-Radiator fan 2 (V177)
P1951 - Movement restricted/Jammed - Intermittent
You'll need a wiring diagram to verify power & ground to fan module. The ecm sends a control signal to the module... verify that the signal is getting to the module. If the fans are separate from the module, check for power to the fans (using vcds output tests). If no power is getting to the fans, then the module is bad. If power is getting to the fans, but the fans don't work... the fans are bad. Make sure to also verify correct ground for the fans... unless they ground through the fan module.
I don't have a wiring diagram handy, so that's all I can suggest right now.
@@EXOVCDS Little update about this issue: I was googling a little bit and found out that at my car both fans should run at the same time, no matter if AC is on or off. In my case, because the smaller fan was not working when AC was off and with those fault codes i've got, i've decided to replace the smaller fan. After replacement, i have erased fault codes and started to obtain situation. Unfortunately, the replacement of smaller fan did not solve the problem because, soon after, i've got the same fault codes again but this time, the problem appears to be less obvious then it was before. I dont know if it is a coincidence or not but now both fans run nice and quiet even when AC is off but it happens from time to time that only bigger fan starts to spin hard and loud like it was before. In the meantime, i have also found out that the control modul for both fans is the integral part of the bigger fan. Considering that, I'm now wondering should i replace a bigger fan also. I mean that's all i can do because, correct me if i'm wrong, but i think i cannot test power and ground cables that goes to fans connector when, at the current situation, problem appears to happen only occasionally (let's say 1 in 5 times or even less).
Replacing the big fan will most likely fix the issue. You can use a multimeter to check "control" from the ecm at the main plug for the fan... similar to what I do in this video:
czcams.com/video/oqdv4cm86Ns/video.html
Thanks alot for the very helpfull information!!
you saved me alot of money the problem was with Thermostat.
Thank you for watching... good to hear you found the fault!
Hey man I recently got a 2001 Jetta VR6 and your vids have been an invaluable resource for me. The car is running great but I have this similar issue where my radiator fan isn't kicking on and I'm experiencing overheating when the a/c is on(climatronic). On a cold start that main radiator fan will be spinning but only if the weather is not too hot outdoors. We've had some scorcher days recently and I noticed on a cold start during those days that big fan won't spin at all. On a normal day if I do a cold start both fans will spin fine(with a/c on) but the big rad fan will just give up once the car hits 190 operating temp. From there the car will run fine with a/c on but the temps start to creep up if I'm idling for more than a half hour or so, all the while the main rad fan won't kick in at all.
I've tried several different things; I checked all the fuses and tried a new FCM and it's the same issue. I figured the next thing I'll try is this radiator fan switch. Now onto my question, if I test this plug and the fan spins fine on high/low, does that mean the switch itself that screws into the radiator doesn't need to be changed at all and my problem is yet elsewhere? Or does that mean the wiring is fine and the switch needs to be replaced? Sorry for the long winded post, not even sure if you'll see this but either way thanks for your invaluable work brother.
Most likely it's a bad large fan.
Hello Thomas. A month ago, I changed the thermostat and the car worked perfectly. But for a week, the dashboard does not indicate that the car is warm and the fan is running constantly. My mechanic does not detect a diagnostic error. The pipes to the radiator are warm but not hot, the fan runs and the appliance does not show temperature on the dashboard. After switching off the diagnostic unit, the car heats up to 90 degrees and the fan switches on and off, after 3 days the problem reappears. Monday we replaced a temperature sensor that is below the sample radiator.
It was repeated again Friday and then, he just hung up the diagnostic tool and the dashboard indicator went up as the fan stopped working. Everything works for now, it is not known when. The coolant sensor has not been checked!
Audi a3 FSI 1.6 2004 manual petrol
Have you checked this sensor already?
fkh161.ca/Audi/A3/BAG_Coolant_Temp_Sensor.jpg
@@EXOVCDS Yes, i change thermostat with new sensor ! The coolant sensor has not been checked! www.audi-sport.net/xf/threads/temperature-sensor-or-connections.413021/
Thank you; it has been of help.
Thank you for watching!
I have a 2009 VW GOLF CITY, the smaller fan on the passenger side wouldn’t stop spinning - Drained my entire battery so I would have to unplug the fuse for the fan every night when the car is turned off. Now my fan isn’t spinning at all but the temperature gauge isn’t showing it’s over heating on the dash. I have switched the coolant temp sensor, I have also plugged my fan into my battery to see if it’s still works and yes it does, I have bought a radiator switch too , my next step is replacing the entire fan or is the fan just spinning without me knowing ??
Both fans should run at either low speed or high speed when either speed is needed. If one fan is working, but the other isn't (when tested as in the video)... spin the non working fan by hand to see if it comes to life. Use a test light to confirm power & ground to the fans when fans are not on (when they should be). At 13 years old there could be wiring problems, the fan control module could be bad... but the fan control module is only needed for fan activation when ac is selected or excessive ac pressure is pressent. .
explained very well. Thank you!
Thank you for watching!
having same on audi TT . but so tight to get to connector, going to try from bottom.
Yes, will be / should be easier from the bottom.
thank , i did it, fan runs, power on the wire. it turns out corrosion on the first fuse. no more over heating and the ac works now. we are going to replace the fuse box any way. we take no chances
Thanks for the update... sounds good!
Hi My fans recently stop working AC and heat work. Large fan spins freely. Small fan is out of alignment and doesn't spin seems to be jammed. Car over heats while in traffic. I have been Jetta 2004 vw Jetta. I check fuse box fuses are good. That's as far As I got.
Does the large fan spin when the ac button is pushed?
If it does not overheat while the vehicle is moving... then the thermostat, water pump and radiator are OK.
Did you bridge the radiator fan harness plug to manually trigger the fans? What happens?
The vehicle should not overheat with only 1 fan working (large or small).
If one of the fans works when manually bridged, but does not come on at idle when plugged in... replace the fan switch in the radiator.
😓😓😓😓 I do t know what any of that means. To answer the question I can. Neither of the two fans work. The car only over heat while idle or in traffic.
Can I ask the relation of the fan operation to A/C turning off/on? 1997 Golf with AAZ Diesel and cooling fan will not turn on when motor is warm (or with the A/C on). Just tried A/C and pushing the button doesn't seem to trigger the A/C clutch (motor doesn't take or release a load) and the air seem to be blowing cold which makes me think the A/C is on (It's also 0*C/32*F right now). Could one component/sensor/switch cause both to go down or is it most likely the control module?
There is power to the fan switch, but with the key off completing the circuits does nothing. With the key on, completing the circuits will only trigger high speed fan.
Thanks!
vanislefaller Sounds like low speed is burnt out. Low speed does not go through the fan module. High speed does (needs key on)... low speed does not need key on.
thank you so much. I was looking for information about if can I short those pins to force fan spin, or can i not.
btw. you are lucky that your plug was so easy to remove - main is stuck.
As you can see... I bridge the power wire with one of the other wires to check fan operation. Year, make, model, engine? Is the engine overheating? All the time even when driving?
I have a dentist appointment in a short while... I will get back to you once I am back home.
Have you bridged the wires? What happens?
@@EXOVCDS thank you for answer. a3 8L1 1,9tdi 2001 a/c present. Engine is overheating. quickly gets 100/120 degrees. Fan doesn't start. So I thought that maybe is faulty. When I turn the core by hand it turns hard - not that easy like small fan from a/c. So I wanted to force fan to start to see if it can turn -because fuse is okay. but I cannot discontent that socket/plug. it stuck. I'm afraid that I will rip off the sensor.
so I left it and I went other way. I connected laptop to obd2 and using vag-com I saw that ecu see different/ lowest temperature. I discovered that temperature sensor has 4 wires so it is 2 sensors in one. fist for ecu, second for instrument cluster, which can be faulty. so I force dash board to make a test. And when all arrows /pointers stops vertically in the middle I saw that temperature arrow wasn't on the middle in 90 degrees but at 100. and later it wasn't move smoothly. I read on forum that there was two versions Vdo brand, which is good and Jaeger, which can gets faulty easily. I took out instrument cluster and see that mine is Jaeger (not Vdo). I also has issue with fuel level arrow/pointer - sometimes stops work So I think my engine is not overheating - but simply Jaeger is faulty. I have to replace instrument cluster. And then after that I will be worry about fan. When my car stays 2 hours off I open the coolant liquid box and touch the liquid by finger and it was just warm, but on the dash board I saw 90 degrees so it is not logic. so I start the engine, wait half hour and discovered that radiator was hot as it should be and bottom hose and upper hose were hot as well so temperature valve must working fine.
I'm not sure about fan but the main reason is dash board.
SO thank you very much for interested in my case and spending your free time to help me. When I get new /used dash board I will try again to disconnect that fan plug and force fan to start. I couldn't find output test in vcds/vag-com to force fan to start.
BTW.
how's your teeth? :-)
greetings from Poland
@@Radek__ Thank you for the update! TDI's take a long time to get warm... quick rise in temperature is usually electrical / sensor problem, just like you discovered. Good job!
Teeth are good, thank you! LOL
So with the switch on the fans should be on low speed then correct? And then kick on and off high speed with the fan control module?
Year, make, model, engine?
Good lesson. I believe you've shown this before. Thanks!
Yeah... figured I would do a recap. Been getting a lot of "my fans aren't working" questions lately.
@@EXOVCDS Hi sir
Sokda Octavia desiel 2008
Radiator fan continue on both
Key off ,fan not stop Battery total Down plz help what can I doo sir
I got mk1 golf 1998 and my raditor fan runs very very slowly when I do that connection. Is the fan bad or what
Could be.
hello, when the water is in 90 °Celsius (194 °Fahrenheit) the heater is still not working. how can I dissolve this problem , please help me
(audi A 3 TDI (2004 years))
Could be a problem with the heater control door or the heater core is plugged... not sure.
Good tips and video!
Thank you!
When i make the Bridge the fans not work only click
Year, make, model, engine?
Hi tom, Is it possible to load gas into an AC system without the compressor Engaging?
Yes... but you don't know if air is in the system. If the charge is low, adding gas while the engine is at idle (AC on) should eventually turn the compressor on (providing that a "low charge" was the only reason for non functioning AC). DIY AC Charge Kits are available, but be careful, as some of them contain Propane... if you ever get your AC serviced professionally, it could end up contaminating their equipment.
Hi Thomas
You mentioned that if you have low speed but no high speed, it's a fan issue. But what about the fan control module that you mentioned controls the high speed of the fan? I have one on my TDI that I believe to be faulty, but how do we check it?
If car has AC.... bridge high speed on the rad fan switch with the ignition ON. If high speed does not come on, check for power at the fan connectors. No power, trace the wires to the fan module. if wiring is OK, fan module is bad.
High speed not coming on. New control module, new temperature sensor, new thermostat and new radiator temp sensor.
What year GTI? One or 2 fans? If 2... both fans affected?
Nice video. I tried to test my climatronic fan (the small one) which does not work on my passat 2004 and found out that the fan connector has 4 pins where you have 3 pins. How do you test the fan with 4 pins?
Which engine? Sorry, I read / replied to your other post first.
The car is on when testing the fan?
Key on engine off.
Speed one should work with key off.
Hi your vedio is much informative. 👍🏻for audi a3 2009 reg
I have Recently replaced cooling fan n compressor but fan still not working well initially it was working with Air con ON but now it’s not working and glow plug light starts flashing in just one week period of repairs.
Please guide if you can?
I'm still at work, I will get back to you later once I am at home later tonight.
Is the engine overheating? Only when at idle or also when driving at steady speed?
Which engine is in your car?
On your car, the radiator fan(s) are most likely controlled by a Fan Module... that is controlled by the ECM. You need to check for a "command signal" at the fan module. If your only concern is that the fans do NOT work when AC is on (but they come on when temperature is hot), then you have to look at the AC system for faults. Check the ECM for fault codes... the flashing glow plug light may or may not be related.
Thomas EXOVCDS 1.6 diesel
Thomas EXOVCDS Thanks
One more thing please about flashing light of glow plug what is the reason?
I put diesel cleaner in fuel tank is it some thing related?
hey tom, i lost the document link you sent me on how to diagnose fan problems, my fans go on speed 2 everytime i switch the engine on and goes off when i switch the engine off.
Send me an email to remind me what the actual document contained.
@@EXOVCDS I found it at TDI club.com
pics.tdiclub.com/data/517/A4_Air_Conditioning_Troubleshooting_Rev_7.pdf
I test the fuse it’s good I disconnected the plug I have power on one. Did the pin thing and the small fan kick in when inside the car put the key on try it with the other one and still the small fan kicks in the big fan won’t move even with ac on. I already replaced the dans both and does the same thing any ideas
Year, make, model, engine? You need to check the wiring / wires going to the big fan. Both fans get power from the same fuse, if one fan works, then the fuse is ok. Disconnect the connector for the big fan and check the wires from the connector going back to the radiator fan switch... you will probably fine bad wiring / corrosion on the power or the ground side.
@@EXOVCDS 2001 vw Jetta Wolfsburg I’m gonna try to do that I check the box on top of the battery looks good but I gotta try to disconnect the fan
You don't have to disconnect the fan... just the fan switch connector. Do the testing there and let me know what happens (like in the video).
Hello I have done the test and the fan won’t turn on, instead I get a clicking noise. Can you help?
I'm still at work... I'll get back to you later today once I'm back at home.
Year, make, model, engine?
I jumped power to both my fans and my passenger fan doesn't work. I guess ill just replace both anyways. :) thanks for the great videos on this issue buddy!
Year, make, model, engine? Does the one that "does" work, come on when triggered via AC or at the radiator fan switch... as in this video?
2002 vw golf tdi manual. The one good one doesn’t turn on with ac turned on :s
I will try the rad fan switch trick in a little bit!
@@EXOVCDS Update: There is power at the rad fan plug and the fan turns on when I jump the pins!
@@2nsane2005 Thank you for the update. If none of the fans are turning on when AC is selected, then there is probably an AC issue / Ac is probably not active. If you are not having any overheating issues, the engine will run fine with only one functional fan... but I would recommend replacing the defective one (or both) to be sure the system is working correctly for the upcoming summer months. If the engine IS overheating, verify that the water pump is working and that the thermostat is opening.
czcams.com/video/GEo9fG9bURI/video.html
czcams.com/video/5nmqsg3Lmdw/video.html
Thomas EXOVCDS I checked my Freon level and it’s super low. I’m gunna recharge it and see what happens
Hey Thomas! I have the same 2.0 w/ AC. Both fans do not come on, but when jumping the cooling fan, only the high speed works, even when bypassing the FCM. Any ideas? Thank you.
Low speed of both fans is burnt out. Replace both fans. You can confirm this by applying power & ground directly at each fan harness plug.
@@EXOVCDSEven if the fans aren’t coming on at all? (High speed doesn’t kick on even when warmed up and driven)
Are you sure the water pump is pumping? Is the thermostat opening? Watch this video... do the same checks.
czcams.com/video/LiDRUWPw_f4/video.html
Hi,I have a 1998 golf 4 Gti the fan only goes on once I bypass the 2 and 3 on the fan plug (the one that goes on the switch) once the key is turned on I replaced the sensor but still it doesn’t switch on the fan unless I have to bypass while the key is on
Could it be the control module?
What is the main problem? Is the engine overheating? When at idle or also while driving?
If your car has AC... the fan should have 2 speeds. Low / 1st speed does NOT require the key to be on... 2nd speed DOES require the ignition key to be on. If 1st speed is not working, then the fan is bad. If the radiator is not getting warm because of a stuck closed thermostat or a bad water pump... then 1st speed will also not come on.
@@EXOVCDS car over heats on both idle and drive…the 1st speed doesn’t go on but the 2nd speed only goes on when it’s jumped as in the video above, I’m suspecting the fan control module? Since it doesn’t switch on the fan automatically when the temperature is high?
@@Chartkingna fans are not needed when driving at steady speed. Your thermostat is probably stuck closed / bad.
Good vid. !
Scope on a rope is always impressive!
👍👍
Hey Thomas, Great video, I am in need of some advice, I have a 2010 VW golf and it overheats in traffic, I checked and neither of my fans are coming on. Any suggestions?
Check power, ground & control as per this video... if this looks like your radiator fan connector:
czcams.com/video/oqdv4cm86Ns/video.html
Hi, I've watched several of your videos and they've been very helpful. If you don't mind, I have a question. My daughter has a '05 VW Jetta 2.5L and the transmission was recently replaced. Right after we got it back, the fans wouldn't shut off right away. Now they won't come on. The car has almost overheated 3 times. I've checked the fuse, the fans move freely and I hear what I believe is the fan control module clicking when the engine is turned off. It has the P0480 error code. I've already sunk $3500 into this car a month after we bought it and really don't want to spend another $400-$800. Would simply replacing the fans fix this? That much I can do myself. Thank you for your time.
The fan module gets a signal from the ECM (pulse modulated signal)... the fan then activates both fans at the same time. If the fuses are ok, the fan module receives a signal from the ECM but the fans are not turning, then the fan module / fans are bad. If I had the car at the shop, I would use a scan tool to turn the fans ON. If nothing happens, I would check power & ground at the fans and would confirm that the signal from the ECM is getting to the fan module. Here's a wiring diagram:
fkh161.ca/VW/A5/mk5RadFans.pdf
Sorry I didn't reply back until now - thank you very much for your help! I was able to purchase a new cooling fan for $100, installed it and it now works. You saved me literally hundreds of $$. And it was so simple. Thank you again!! Next on to the O2 sensor and door locks.
Thank you for the update!
MK5,TDI ,with A/C.
Big fan ON all the time, hi or low speed. Goes on high speed even when i pull over on the highway after driving constantly at 80mph. Car never overheats. Small fan never turns on, at all, no matter what i switch on. Ideas?
I would start with checking for fault codes (doesn't matter if check engine light is not on / off) in the ECM and any other modules. Then I would do an "output test" via the ECM of the rad fan(s)... to see if they behave correctly. Then I would check a wiring diagram to see if there's something that could cause the issue you describe. Nothing that I have run into in the past fits what you are experiencing. A faulty temperature sensor can cause the fan to be on all the time. If the ECM does not know the actual temperature of the engine, it may turn the fans on full tilt to protect the engine from overheating. The small fan could be burnt out.
So i went to a friend that has VCDS, tryed gettin in the fan controller and do a test on the fans, could not connect to it.. So we are assuming that its faulty, and it went int it's own limp mode and goes stays on low/high to protect the engine. I have a new entire fan assy ( the entire thing with both fans from ebay -$99) that ima put in . After i take the old one out, will take it apart and see if i can find the problem ( im throwing it anyways, might as well do some explor9ing)
semecristian Thanks for the update! Let me know what you find.
I applied voltage to the small one, no response, and the big one had decent aluminion oxidation on the controller. Seems they are the original ones, car has 200k miles, i guess they did their job.
The new fan assy from ebay is Made in the USA, VERY good build quality and parts in it, it amazed me how good it looked and felt. And it works perfectly, easy to change, just unscrew 4 corners and take out from the bottom with car on a lift.
Thank you for the update!
Hi Thomas, thank you for this nice video. My car fans are running properly with jumper test, but not kicking when engine overheats! However, thermostat and temp sensor replaced with new, water pump no signs of ware out, cabin heater working fine. Is it possible that the radiator is clogged? My car is VW T4, 1993.
Possibly. Are you sure that there is no trapped air in the engine? Do you have flow back into the coolant reservoir?
I opened the air tap until water came out then after few days I tired to remove the upper radiator hose for little while but no good result.
The weird thing is when I tried to remove the switch sensor, no water came out, while the water container was full!
How to know if there is back flow?
@@navictor if no coolant came out when you removed the radiator fan switch, then you have air in the radiator / system.
Okay, thanks a lot
What temp does high speed kick on at?
The temperature ratings are stamped on the sensor / switch.
Thomas is there anyway to get a hold of you I have a very odd ball problem everyone I talked to never herd of it and was wondering if you did
Summarize here.
Hello, good video first of all thank you. My car's fan is not stopping even i turn off the car. When i check it from VCDC air control sensor is blown (g238). ıs it related?
No, probably not.
Check it / replace it and see what happens.
Year, make, model, engine?
@@EXOVCDS 1.6 tdi 77kw. 2012. Audi a3 . Air quality sensor is not working. Outside temp. Shown 18celcius but it is not.
Air quality sensor measures air quality... too much exhaust or oil smoke under the hood should cause the climate control system to close the fresh air door, so that the fumes do not come into the car when the heater or AC is used.
I have seen this code on vehicles and the fans were not always on.
@@EXOVCDS thank you very much. I just removed the sensor put it in the sun and blow with air. It is ok now. Shows a value =7 now (iread it from vcdc) fan continues to spin even the car stopped. I think there is something wrong with the car. Thanks for replies.
@@necromecro if engine computer has no fault codes for radiator fan, then the fan control module is bad.
have you seen the video length???
Badgertronix I was hoping no one would notice! To not have uploaded it or to have deleted it... would have been serious bad luck!
Hi, I got a 2006 Jetta & fans are Not working, not when the AC is on, none at all. NO check engine or temperature light on, even in this July Heat. Any ideas? - thanks
A4 version or A5?
(mk4 or mk5)?
Fan control is different for the 2 generations.
Mk5.
Trying to figure out how to just Unplug the dumb thing w/o breaking it right now, haven't had it apart before. If I short the connector will it turn on the fans?
@@leeisenberg your fans work different from this video. Watch this one:
czcams.com/video/oqdv4cm86Ns/video.html
You can use a regular multimeter to get / check the same voltage readings. You don't need VCDS & laptop. Just let the engine idle and check for a voltage on the control wire. Turn on AC and check if the voltage changes. Check the thick wires for power & ground.
Okay thanks man. Will do, take care.
Hey man thank you so much for this video, you were very to the point and i am so grateful for that, but my issue is sort of perplexing. This video is old so i understand if you cant/dont get back to me but Im frustrated and having a harm time finding help on the forums.
I have a 2003 Jetta with the 1.8t that radiator fans wont kick on. I tested both fans independently and they both have full function of high and low speeds. However the car will not power fans unless i have the AC on. The AC blows hard and cold and the fans run but the car will start to run hot if the AC & inside fan are off. My temp gauge is working and my actual values will show my coolant temp get to 230° and thats when i kill the car because i dont want to damage it. Do you have any idea what could be going on? I replace the fuse box on the battery and that has changes nothing.
I read somewhere that the thermo switch could be bad? Seems a lot cheaper than the fan control module but i dont know how to condemn that
Fans are not required at cruising speed. If the vehicle overheats while driving at steady speed... then the thermostat is probably bad / stuck closed. If the fans do not come on when triggered at the rad fan switch (harness plug), then look for a wiring problem or a power / ground problem.
Good vid man appreciate it
Thank you for watching!
Let me know if you have a specific issue... year, make, model, engine?
If it's overheating, make sure to check for water pump operation (coolant flowing back into the coolant reservoir).
Good info
A short refresher for all the recent cooling fan questions.
Cheers for the video its helping me narrow my issue down. Wondering if u could provide some info?
2011 ibiza st 1.2tsi. i have replaced water pump, thermostat and expansion tank and cap.
Coolant still boils over and noticed radiator fans wont come on. Having checked your video ive bridges the fan switch and pins 1-2 work for low speed and pins 1-3 work for high speed which pointed me to replace rad fan switch. I have installed new switch and still no fans?
I have 1 fault code on vcds for a/c low pressure but not sure if this would stop fans working?
Top rad hose gets hot and bottom rad hose is slightly cooler that the top all other hoses seem to have flow apart from the expansion return pipe seems weak flow rate if other rad pipe squeezed it increases like air trapped.
When coolant boils it escapes the expansion tank until coolant low when left to cool its sort of drunk awa into the engine requiring around 300ml top up. The car doesnt seem to over heat and nothing leaking on the driveway.
Any info im at a loss with this
If the fans don't come on... it has to overheat (also why coolant is boiling over).
Make sure that the reservoir cap o-ring is sitting correctly on the inside of the cap.
How firm are the radiator hoses once the engine is warm? Very firm / hard to squeeze? If yes, let the engine cool off and check if the hoses remain stiff even after the coolant is cold. If yes, then the engine has a head gasket issue.
If you manually trigger the radiator fans and leave them on... does coolant still escape from the reservoir?
I can't help if you don't reply.
@@EXOVCDS sorry bud haven't had a notification to say you replyed.
Hoses get hard but nothing extreme there still slightly squidgy.
If pressurised and left over night pressure escapes and the rad pipes are super soft by morning
I haven't actually tried to run around with the fan bridged that's my next move.
I suppose this should then tell me one way or another if it's exhausting into the coolant or this is just simply over heating.
Would the partially blocked matrix cause these symptoms?
In all the years I have worked on VAG vehicles, I have never come across a blocked or partially blocked radiator.
If the rad fan sensor doesn't get warm / hot, I guess it could be... but why doest the temperature gauge go higher?
Have you confirmed the accuracy of the temperature gauge? Compared it with the value that the ecm receives (using a scan tool)? O-ring in the reservoir cap ok?
@@EXOVCDS it is very strange, I've used vcds to pull live data and the only thing a miss was the fan switch reading -47c I've replaced this but still no fans running.
Top rad hose is hot bottom slightly cooler but warm not cold.
The old thing I can think of is the matrix is reducing the flow rate and this in turn isn't reaching the rad/fan switch at the correct temperature but this is just a theory and I'm struggling to prove....
Think it might have to go to main stealer
For fabia 1.2 azq 2003 how do I check if both fans work properly?
Now the big fan works and if it I starts up AC the speed increases but the second fan d'not start.
At very high temp the big fan starts to spin very hard and the second fan d'not start.
What woult be the cause?
Thanks!
The fan is probably bad. Check for power at the small fan, when the big fan is working (I think they should work at the same time, but I can't be sure since we do not have Ford Fabia here in Canada). Use a test light to check for power at the connector.
Hi,
I started the car and the air conditioning and I checked the voltage for the soket from small fan. It seems I have no voltage on those cables.
It would have to be voltage on those cables when the big fan starts up.
You'll need to check a wiring diagram to see how things are connected. It could be that there is a separate fuse for each fan.
hey Thomas I appreciate all the content I know this video is old but any chance you see this I have a 04 bew Jetta that I recently bought the fans don't kick on for anything and the car has no ac. I tested the thermo switch like shown in the video and only one fan kicks on lo . I went ahead and tested each fan individually and both hi and lo worked on both. all fuses and connections look good any idea as to why the fans wouldn't be working? I replaced the thermostat and coolant temp sensor hoping it would help but nothing
Watch the first 3 minutes of the following video... report your findings:
czcams.com/video/LiDRUWPw_f4/video.html
TDI engines take a long time before the fans come on.
If the engine is NOT overheating, then the water pump is OK.
If the engine IS overheating, even when at cruising speed, then the water pump is bad.
@@EXOVCDS hey man thanks for the reply!!! It doesn’t overheat at all but even after letting get to operating temp the fans don’t kick on and there’s never ac. I do have flow and there seems to be heat inside so should I change my thermostat again ?
( also I noticed that my top radiator hose is very warm after running and the bottom one that goes into the thermostat is not. This indactes a bad thermostat right ? I might have got a faulty one from the parts store)
@bryanmartinez8191
No AC as in not blowing cold (but has AC)... or no AC in the car (no compressor)?
If you have AC but the fans don't come on when AC is selected, then you might not have enough AC gas in the system.
Like I said, fans take a long time to come on with TDI engines.
Hold the rpm at 2500. It'll take more than 10min before the bottom hose gets warm.
As soon as the thermostat opens a little, it will close again due to the cooler coolant entering the engine.
Eventually the radiator will get warm and the rad fans will come on.
If no fans or only 1 fan comes on when the radiator fan switch is bypassed, then you have to look for bad wiring/ corrosion... since you said both fans work at low & high when activated directly.
@@EXOVCDS it does have a ac compressor, I failed to mention when I put a paperclip in the fan switch only one fan came on
Hi mate so I’m trying to find my radiator temp switch on my Audi s3 8p and can’t locate it could you help me pls
Controlled by the ECM. The ECM monitors coolant temperature and then sends a signal to the "radiator fan control module". Check the ecm for fault codes. Which engine? Overheats only at idle or also when driving at steady speed?
@@EXOVCDS it’s 2l tfsi mate so I’ve got the part and just needs fitting but can’t figure out where it goes it’s a radiator temperature fan switch
@@jmalmal93sg17 sorry... your reply was in the spam folder. If the sensor is not in the lower radiator hose, then it is either in the coolant flange at the side of the cylinder head or mounted on the water pump under the intake manifold.
Thanks!
Hi Brad, that's too much $.
If both fans worked (low & high) when you bridged the rad fan connector, then the fans, fan control module & wiring are ok.
I assume the engine is overheating / you're getting the red light in the dash?
3 common things that can cause overheating.
- water pump
- thermostat
- bad rad fan switch.
No heat inside the car means the water pump is dead or the heater core is plugged.
If the top rad hose is hot (can't hold the hose for more than 10 seconds), then the thermostat is stuck closed or the water pump is no good.
If low speed fans don't come on when AC is selected, system might be low on charge or there's an ac fuse that's no good.
If you manually active low or high speed... will it cool the engine, if yes, bad fan switch.
I haven't seen many plugged radiators.
Leaving work soon. Might have more input once I get home.
@@EXOVCDS That's a small amount for all the help and enjoyment you have given me over the years. 🙏
Yes, overheating, and no AC. I don't think these fans have worked for the 5 years she has had the car. Water pump is fine, heater works, replaced the thermostat, FCM and temperature sensor switch.
No fans ever, unless I jump it. Don't come on when AC is selected, but as you say it could be low, but they don't kick in when it gets hot (checked with VCDS-Lite). Is there another fan switch somewhere? I'm thinking of pulling the FCM from my Jetta and trying it, even though I plugged the new one into my car to test it and it was fine. Is there a way to test the sensor switch? I tried a ohms test, got nothing. Always worried about buying parts that don't work...
@bradsherwin4568
Is coolant flowing back into the coolant reservoir when the engine is idling?
Could be an air lock / blockage in the return / bleed hose.
I'll reply again later tonight once I'm at home.
@@EXOVCDS Yes, coolant is flowing back. Had to drain and refill a few times after overheating and the temp sensor replacement.
@bradsherwin4568
How warm / hot is the radiator core getting?
Monitor coolant temperature via scan tool... periodically feel the radiator core with your fingers between the rad fans.
The core should start to get warm after 87c.
TDIs can take quite a while to get warm. Hold the rpm at 2000 till temperature gets to 87c / 90c.
If the thermostat is new and the rad fan switch is new, the only thing keeping the switch from getting warm is the radiator (core is plugged).
To check, disconnect the lower rad hose at the thermostat flange. Route it down under the car into a catch tray / shallow bucket (front of car on ramps would be helpful).
Have your daughter start the engine while you monitor flow from the hose.
Coolant should rush out as rpm is increased.
Fluid level in the reservoir should drop quickly.
If coolant does not rush out and the level in the reservoir does not drop quickly, then I would suspect the radiator.
If you activate the fans manually, can you keep temperature from getting too hot?
Hi I tested my fans and I can get them to go on with the key on on high when I jump power. They do not work on low speed with key off when I jump power. When I spin the fan on the passenger side it’s sounds like it’s rubbing a lot so is it possible my fans need to be replaced. My problem is my air conditioner does not work. When I press the AC button it lights up but the fans do not turn on and the compressor does not engage
Both low speeds are probably burnt out... you need to replace both fans. To be sure that they are burnt out, you need to verify that the fans are actually getting power when you activate low speed (manually or with the AC button). Raise the front of the car (support it safely with jack stands) and gain access to the radiator fan harness plugs. Disconnect the plugs. When low speed is on, one of the 3 wires (each harness plug has 3 wires) should have power. If yes, then the fans are bad. If no, then there is a break in the wire... somewhere between the radiator fan switch and the 2 fan connectors.
@@EXOVCDS thanks for the super fast reply. I can’t tell u how much I appreciate it. I’m trying to keep my 20 yr old VW in top shape!! Have a great day my friend
Keep me posted with what you find / end up doing.
@@EXOVCDS I def will. I’ll test it ltr. If my fans r bad could that be why I have no AC?
AC light in car lights up when pressed & fans blow, just warm air. Original Compressor doesn’t turn on
If compressor does not turn on, then the system is low on charge, the pressure switch is bad or the compressor clutch is bad (or something else). If the compressor turns on, but the fans don't, then the fans are probably bad. Either way, you need to solve the fans... since they need to cool the condenser when the system is working. Take the time to confirm / fix compressor activation first... in case you need to spend a bunch of money on that first. AC should still work with non working fans... it just won't be as cold at idle, compared to when the vehicle is moving (air flow through the radiator for cooling).
Thanks, nice vídeo.
Thank you for watching!
What if only one fan comes on. I checked that fan that didnt come on with current going directly to it and it worked. Could it be the relay?
Year, make, model, engine?
If the fan works when you directly apply power & ground, but does not work when bridged at the radiator fan switch... then there could be a wiring problem (broken wire, corrosion, bad resistor pack (if low speed does not work). Depending on the vehicle (my first question) low speed resistors are inside the fans or outside of the fans.
@@EXOVCDS 2001 vw jetta 2.0
@@EXOVCDS the small fan comes on when I bridge the switch, the large fan does nothing.
Low speed is probably burnt out on the large fan. With the key ON, bridge the radiator fan connector to get high speed for both fans. If high works for both, check for power at the large fan connector when you have low speed activated. If you have power at the fan connector when low speed is active, but the fan does not move, then the resistor inside the fan is bad.
Hey, ive got a 1999 golf with a vr6 swap.. bought it cheap just wanted something fun to rip around with and work on, cars been overheating and fans wont kick on, i did what you did in the video and when i connected the paper clip the fans kicked right on. Would you say i should replace my fan control unit?
or i was thinking just hooking up a manual fan switch, race car
Thermostat
Hi sir Thomas
My car sokda Octavia desiel
Radiator fan both on continue not off
Key off but fan not stop Battery total Down
Plz tell what can I dou help plz
What year? You have to look at a wiring diagram to see how the fans are controlled.
2008 model sokda Octavia
Octavia 1 or 2? 1.9L BXE TDI?
You need to be more specific so that I can find the correct wiring diagram.
Hello Thomas , I need your advice, please help me! in the morning when turning on car(audi A3 TDI 2004 ), the radiator fan running too, how can I solve this problem?
Is the AC on?
Scan the car for fault codes.
Check temperature sensor values with a scan tool.
@@EXOVCDS thanks for everything, It was a water sensor problem, I checked only 2 and here was a 3 :D
@@natiapkhakadze292 Thank you for the update!
Just curious, what kind of headlamp are you using? I'd love to get one, it's really bright!
czcams.com/video/vh5WncJxba0/video.html
Hey any reason for the 30 amp fuse to blow. Mine was. Thx Sir
Short circuit... old / stiff fan?
@@EXOVCDS Actually new fan from 1aauto. Prob not the highest quality but only 1 month old. This is the first time in my 01 golf that this fuse blew. Both fans sound like they’re rubbing as the spin. Small fan only spins for a Second by hand. Large one will spin for like 5 seconds after I spin it
@@pujo28 Check a wiring diagram to see what else is on that fuse (other circuits). If the fuse constantly blows, then narrow each circuit down and follow the wiring. If the fuse has not blown since replacing... keep an eye on it.
@@EXOVCDS thx for the replies. I’m also gonna replace ran assembly since they’re rubbing a lot and not spinning freely. Otherwise I’ll watch the fuse. I’m assuming it’s from the fans being hard to spin. Thx again
The fan world when i touch the pins but wont work when the engine reaches operating temperature, what to do?
Year, make, model, engine?
2006 vw polo 9n 1.4 bky. I think i found out that i need to replace the radiator fan switch
@@dennyl9914 Is the radiator getting hot? If not, then the thermostat is stuck closed. If the car does NOT overheat when you are driving, then the thermostat is OK.
Thomas,
I have a Mk4 Jetta 2.0 and the fan cycles on and off while the car is idling. I couldn’t find anything on Vortex about an issue like this. Should I check the module?
How often / quickly does it cycle on / off? Doe it only happen when AC is ON?
It "should" cycle at an even pace. Change the radiator fan switch to see if things change.
Thomas EXOVCDS it cycles every 3 seconds continually without stopping
Disconnect the radiator fan switch... same thing?
Does the engine have AC? What year is the car?
Hi Thomas.
I have 2002 a4 1.9 tdi.
When i turn on ac one fan comes on.
My question is, without ac on when the car heats at normal temp. should this fan comes on ?
All time only belt driven fan spins not other fan.
The fan or fan control module could be burnt out. Electric fan only comes on when AC is ON or when engine temperature is too high.
Thomas EXOVCDS
Teperature stays at normal 90 C
But i just bought the car and never hear the electric fan runing without ac on.
Thats why i ask.
Like I said... electric fan only runs when AC is on or when temperatures are too high. If temperatures are always normal (below 110c) then electric fan is not needed.
Thomas EXOVCDS thank you so much. Because i was worried about this.
Thank you!
Thank you for watching!
hi thomas i have an Octavia Skoda mk1 and the radiator fans do not work and i am thinking to try checking the fuse for them but i do not know which one is it..
can u help me with this thanks?
We do not have Skoda in Canada... I would have to find & look for that information. I will get back to you later today.
Sorry... year? Engine?
@@EXOVCDS well thank you for your efforts but i got it finally.
@@anaskazkaz6522 thank you for the update.
Sup Thomas, I got bad aux fan (ac fan) then I drop the whole assembly and replaced it for another one (oem but used). It did worked, but it stopped too after a while. I turn the ac on and the aux fan won’t come on.
I have a coolant system code that I believe it’s the thermostat (which I’m gonna replace next days) do you think that the cooling failure could interfere at the aux fan, once the car don’t get really hot cause the thermostat is stuck open?
What would do in this case?
Thanks in advance
Year, make, modle, engine?
Thomas EXOVCDS 2006 Audi A3 2.0t FSi
Both fans should run whenever fan operation is needed. Since you bought a used unit, it could very well be that the used small fan is also no good now.... or the fan module that controls the small fan is no good. Thermostat code does not affect fan operation.
Hi I’ve golf vw 2003 .
Temperature never goes over 87 hoses are hot so no air trapped .
Bridged high speed fans work not low speed .
Fans only work when A/C on ,I’ve checked fuses one had blown but changed (black box on battery)
Changed radiator switch,would the relay under the battery sort this?
Thank you
Wait longer... low speed will come on. Low speed is same speed that comes on when ac is on... meaning that low speed is ok. Low speed does not go through the fan control module unless ac is on. If coolant temperature stays low, then the thermostat is opening early / not closing. If you let it idle long enough, temperature will climb to 95c and low speed will come on.
I drove for 2-3 miles yesterday let Idle for hour 10 minutes fan didn’t come on .
Temperature gauge never went above 87
I’m a little confused,the car diesel so I understand it takes awhile to heat up
I didn't know it was a tdi... tdi's draw in a lot of cold air during each intake stroke.The cold air absorbs temperature as it is compressed. On top of that, if the thermostat is sticking open... the engine can idle and the fan never has to come on. Hold the idle at 2000 rpm. I bet that the fans will come on by 10 to 20 min.
I’ll tell you the story what made me think there’s issue .
I was in traffic and the engine just cut off ! (A visit vw workshop came up ,oil warning light )
After 5-10 minutes I managed to start carry on my journey hit traffic again ,it cut again.but no warning lights .
I got it home called broke down company,he came plugged in OBD no codes .
I put it down to the car not like the heat ,was a hot day and traffic was heavy.
2 wks later it happened again but didn’t cut out ,it tried felt like it suck the car back ,got it home pop the hood and watched to see if the fans come on ,they didn’t but the car did cut off again so thought it was the fans .checked fuses noticed one had blown.
Hey Thomas, with your help I was able to sort out my wheel bearing issue 3 years ago big thanks to you. But now with a new car(VW golf 6), my fans won't turn on. The car can overheat in hot temperatures at idle when I'm stuck in traffic for example but is okay when riding. Do you got any idea?
You need to check power, ground, ignition on and fan control at the main fan connector. It could be that the fan module is bad (located inside the large radiator fan). You can test for power, ground, ignition on and control with a multimeter. Similar to this video:
czcams.com/video/oqdv4cm86Ns/video.html
Instead of using a scan tool to activate the fans, simply turn the ac on.
@@EXOVCDS I plugged the fans directly into the battery. They're both working. I also saw that I had a blown fuse. I'll keep you in touch
@@EXOVCDS Also, I scanned my car via VCDS in a shop not too long ago and the codes it threw out were about the fans not working and the secondary water pump. From what I have been told, the error is intermittent and I may have a ground issue
My instructions were for mk6... sorry, I did not know that you have the old fan setup.
@@EXOVCDS no no, I DO have an mk6 tdi 110hp
So i bridged the negative and positive both fans kick on but they neither kick on when i turn the a/c on , what would be the cause of that ? Yesterday the car started to over heat and then the heat gauge started going down on its own and the fans never kicked on i have a new radiator water pump and i have not yet replaced the thermostat but still wouldnt cause fans not to kick on /:
Nemesis X What year / model / engine? Sounds like there are 2 issues. Fans not coming on causing overheating and fans not coming on when ac is selected.
If the engine doesn't overheat as long as the car is moving (air flow through the rafiator), then the thermostat is ok.
Your ac could be undercharged, the ac button could be broken, the fan module could be bad. Focus on why the fans aren't coming on to prevent overheating... once that is sorted, you can focus on the ac.
The car will run for hours and it not overheat but when i did run it on the road for alittle it overheated alittle and it started to cool itself down without the fans , 2002 volkswagen jetta 1.8turbo could it be the sensor in the radiator ?
It only overheats when moving sadly
Or while i was driving around the block about 4 times
Nemesis X It's overheating at slow speeds because the fans are not coming on... the thermostat is OK if it does not overheat at higher speeds. Did you bridge the sensor in the radiator? Did you check the fuse on top of the battery?
Hey man I have a 03 20th mk4 GTI 1.8, 6 speed. neither rad fans come on, they work when I unplug and replug the green battery box fuse but only spin for a few seconds with engine off ac on. only throwing code for o2 sensor voltage but I just replaced that. any ideas?? I replaced all three fuses and ordered a new box coming in a few days... but im nervous it wont fix the issue
Overheats all the time or only at idle?
@@EXOVCDS not all the time, only at 60 mph high load like on a hill. drives around town with none and at idle overheats after sitting
@@ThExHaLoxMASter water pump impeller could be slipping.
@@EXOVCDS oh no... I thought it was overheating bc no fans came on and when I down shift to increase rpm therefore coolant flow they come down. wouldn't that indicate the pump being ok? im not sure man.
@@ThExHaLoxMASter 60mph should not need the fans... how much heat can you get inside the car? If heat comes & goes, then the water pump is bad. You can trigger the fans manually at the radiator fan switch... when it gets got at idle, trigger the fans. If the engine doesn't cool down, then you have bad circulation / bad pump.
Do you know where it is located on the newer B8 Audi A4 2010 premium?
Different system.... controlled differently.
What's the problem? Overheating?
It just does not come on, and I believe for driving it for a couple miles it just shut off my engine and came right back on when I cranked it up. So I blv that was the caused of it
I don't understand what you mean. If the engine shuts off (stops running) the radiator fans do not have anything to do whit that. Record & post a video of the problem on your youtube channel... so I can see what is happening.
Hi Thomas, thr coolant fan on my audi a3 8l was not working so iachanged the fan , and now the tempreture still goes above 90°
and rediatore on the drive sied is getting hot but other wich is ac fan rmains cold.
do you thinks is it the radiator? thank you
Thermostat maybe.
thanks alot for the infomation! but wont be the control mudol switch no? because the coolant fans work in normal speed and high speed.
You said that the temperature goes above 90c and that the radiator is NOT getting warm. If the radiator is NOT getting warm, then the fan switch will not get hot and it will not turn the fans on.
Which engine? Does the water pump pump coolant? Do you have heat inside the car?
yes the radiator is getting hot but only where the bigger fan is but on the side of smaller fan remains cold
on the carrige way and motoway it gets really hot
I have a 2006 beetle 2.5 hatchback with a non operating radiator fan. The engine has never overheated even when driving longer distances. Weird. My temp light on the dash works so Im puzzled. I believe this is the reason my AC is not working but I will check these connections before ordering the very expensive single fan with the control module. Can I check the control module itself? I had FCP euro check the proper fan control module with my VIN but sadly was not the one as mine is the module attached to the single fan.
Watch this for testing steps.
czcams.com/video/oqdv4cm86Ns/video.html
I have audi a4 b7 1.9tdi when i put keys into igntiton and put it to on postiton the fans come on and switch it all off and retry everything is fine why is this ?
jake chapman not sure. Check for fault codes (in all applicable modules). Run output tests to see if everything checks out as it should.
Thomas EXOVCDS i will get vag com on it also sometimes the eml light comes on and the error code is po672 and po673
Both are glow plug codes, shouldn't have an issue with rad fan operation.
What should i check to fix glow plug codes car runs good apart the code being there and the fans come on sometimes when putting keys in ignition what should i check
jake chapman Glow plugs can be checked with a test light.
I have experienced occasional overheating in traffic jam this summer that I could revert by turning on AC. Is that caused by a faulty radiator sensor or should I check something else?
Thanks beforehand.
Great video!
Year, make, model, engine?
@@EXOVCDS it's a 2003 VW Golf 1.8T
Thanks!
@@EXOVCDS Any hint about that?
I have also noticed a very light hesitation between 1.600 and 2.000 rpm aprox. Could it be connected to the main heating issue?
Cheers.
Sorry, I didn't get a notification for your first reply. When you turn ac on, the fans come on. If they don't come on by themselves, then check the radiator fan switch & wiring.
@@EXOVCDS I think they turn on but in a couple of times recently they didn't. I will make sure they start by themselves and let you know. What are the expected start temperature for low and high speed?
Thank you!
Yaa
Yoga Association of Alberta?
Yet Another Acronym?
York Art Association?
Yet Another Addiction?
Young American Artists?
My favorite... and probably what you meant: You Are Awesome!!!
Thank you for watching!
Thx for the video--Im wondering how u so easily pulled the plug off the switch mine isnt coming. I looked at the pics on Rockauto of the switch and it looks like more then one edge to overcome--Thx
Year,make,model,engine?
@@EXOVCDS 2001 Jetta 2L inLine 4, 4 door--The fan doesnt come on w/ the AC on and fan on low thou the AC doesnt work anyway. Would that technique work w/ the AC on and fan on low even if the AC doesnt work on '95 Roadmaster 5.7 Limited 4door? Thx
@@kurtjohn5554 if the ac is low on charge, fans will not come on, because the compressor does not turn on. The rad fan switch has a single locking tan. Push the connector towards the sensor (to unload the locking clip) and then pull back on the release tab & pull the connector off. If the car does not overheat while driving, then the water pump & thermostat are ok. If it overheats while driving, then the water pump or thermostat is bad. If you have no heat inside the car, then the water pump is bad.
@@kurtjohn5554 I don't know anything about other makes & models, sorry.
@@EXOVCDS Danke-- If the Jetta has no AC charge and the engine is not running only the key is on shud the fan start w/ the AC button on and fan on low?
Hi Thomas my skoda Octavia 1.9 tdi 2007 ac not working at idle and car moving ac on pls help
Are the radiator fans spinning at idle?
No
@@sagarjhambhulkar6270 Do the fans come on when the engine gets too hot? With a TDI, it can take a long time for the engine to get hot enough to turn the fans on. You will need to check a wiring diagram to determine how the fans are turned on when AC is ON. It could be that the fan fuse is bad (the one on top of the battery). I'm not sure if your Skoda has the same fuse box by the battery, if yes, check the fuse. If your Skoda does not have the radiator fan switch (like in this video), then the fans are controlled by the ECM (sends a signal to the Fan Control Module that is located behind the large radiator fan). In that case, you will need to check for a "signal" from the ECM at the large fan connector... if a signal is present, but the fans do not work, then the Fan Module is bad (but first verify that battery + & - are present at the large wires of the connector.
czcams.com/video/oqdv4cm86Ns/video.html
@@EXOVCDS
When the car is in motion the ac gets ON but on idle even if the engine rpm is increased, the ac remains OFF.
The radiator fuse and also the ECM is Ok.
@@sagarjhambhulkar6270 The AC is not cold at idle because the fans are not on... when the car is moving, there is lots of air flow through the AC Condenser (cooling it). You need to determine if the fans come on "without" AC... that will tell you if you have a fan problem. Did you already check for battery + & - at the radiator fan connector? Did you check for a signal from the ECM? I have not looked at a wiring diagram to see how your fans are triggered (old way like in this video or by PWM signal like in the other video). I have to leave the house now... I will check back later. Post a video on your channel so that I can see what your Radiator fan setup looks like (old style or new style).
Definitely not easy to get the fan switch off... any tips?
Year, make, model, engine? The more info I have... the better I can help.
@@EXOVCDS 2005 VW GOLF 1.9 TDI
The connector has a small tab that needs to be released. Push the connector towards the sensor and then pull the release tab back, at the same time pull the connector off of the sensor. All VW / Audi connectors work the same way. Practice on one of the connectors at the engine. Like this:
czcams.com/video/3GBtR7fpvyY/video.html
@@EXOVCDS thanks! I’m starting off with triple checking the fuse box on the drivers side door panel with a test light. Should 5, 16, 25 all light up when connected to the negative battery terminal? Only some of the fuses seem to. Fuses don’t look broken to the eye, but just wanting to make sure. Thanks for your time.
@@EXOVCDS never mind... dumb question. Got the connector off. Thanks
Hi I wanna ask you something i have an audi TT 1.8t 132kw 1999 and i spend like 600 dollars on that shit so my problem is in traffic my temp comes to 95-100 and after 20sec colling goes down its fine no problem with that but when i turn motor off temp raise up to 110 and fans dont give a shit about it. I have new fans and thermostat as well. Thank you for response.
Low speed fan operation is triggered by the radiator fan switch that is mounted in the radiator. Engine temperature is measured at the coolant flange that is mounted to the cylinder head... the radiator is not the same temperature as the cylinder head when the engine is off, because the water pump is not pumping warm / hot coolant from the head to the radiator fan switch. Eventually the heat from the warm / hot coolant gets transferred through the coolant to the radiator and the radiator fans might come on... it all depends on timing / conditions. But in general, that is the normal operation. Some 1.8T engines have an electric water pump that circulates coolant when the engine is off... to help dissipate the heat better. All engines from all manufacturers "heat soak" when the engine is shut off (engine stays / gets hotter than the radiator).
So in general its ok? Im just worried about that temp like 110 is really hot and when i open the hood i can even see it. So i cant do nothing with it? I worry about gasket.
You can see the temperature?
Check if you have an electric water pump... if it's running when the engine is off, things should be ok. Install a lower temperature thermostat to see if that makes a difference. Make sure that your current thermostat is working correctly. Make sure that your current water pump is pumping correctly. Make sure that the temperature sensor is accurate and that the dash gauge is accurate. Make sure that the radiator fan switch is working correctly. 1.8T engine run hot / feel hot when the engine is off & the hood is open.
Can see the heat coming from it. Pump is driven by belt so dont have electric. I try to solv it somehow. Ty for your time and have a good day.
There might be an "auxiliary" electric water pump... sorry about the confusion. The main pump is driven by the timing belt... some 1.8T engine have an "additional" electric pump that only pumps when the engine is off (after shut down for 10 min).
my fuses require PLIERS to remove them from the battery fuse panel and to get them back in, its insane, brand new one too :\ about to go test this, placed an order for new fans, hopefully i can call and cancel. I tested the pins but i realized i didnt test the pin for power which im going to go out with a multimeter and see since i dont own a light for some reason, thanks for this :) I was bringing back the r32 from the dead and was idling it and putting air in the tires and on my 3rd tire i heard a weird noise and looked and it was smoking, it was max temp and bubbling coolant out, ran in and turned it off and opened oil dipstick/cap to let as much heat out as i could and then turned on heat full blast :( my baby!!!!! stupid fans dont turn on at all even jumpered
so my plug gets 12.578v at it and the other two pins are getting 0.002 ohms and the other is 15ohms which is the top pin if they were vertical slots and power being bottom right. I assume the high resistance is the fan module and it opens up when the car is on right? so its probably working fine. Either way it looks like I need fans then right? Or should i wire up some double a batteries and tape em together to test the actual fan clip and give them power (i already tried at the triangle 3 wire clip with it off and on for both speeds and got nothing).
EDIT: going to go apply some 12v to the fan harness. at the fan harness after the module or wherever it comes from that end had 0 voltage , should it have any voltage coming out of it? probably not right, it would drain the battery if sitting off if it goes through a module? on just the fan side of that plug i applied 12v (as best as i could with series of double a batteries LOL and verified with multi) and ap plied to both high and low and got nothing. I tested ohms on the ground of fan plug side to high and low and i got OL.... fans need replaced right? Thanks
Yes, fans are bad if you do not have continuity at the fan harness plugs (checked across brown wire and one of the other 2).
Low speed fan operation does not go through the fan module. The fan module is only there for ac low speed, high speed and ac cut out max speed... all 3 require ignition to be on.
Low speed does not require the ignition to be on... that is how the fans are able to come on after parking a vehicle.
@@EXOVCDS thank you kindly. On plug itself for fan continuity would go through both right, on or off. Also resistance would be around 1ohm right? Not "OL" like I got :( I just decided to do FCPEURO fans x2 since lifetime warranty, now to get this low r32 into the air to drop the fans haha.
Yes, fan should have continuity on or off. No continuity between brown wire and one of the others means that the circuit is open / bad. You can have a burnt out low speed, but high speed is OK. If one circuit is bad, replace the fan.
@@EXOVCDS just wish there was a way to tell when they were going other than checking low operation every so often. That mod may come into play but cutting out the alum plate seems ugh
If the fans don't come on could it be thermostat?
If the needle stays in the middle, then the thermostat is ok. How long are you letting it idle? It can take 15 minutes (or longer depending on ambient temperature) for the fans to get triggered by the rad fan switch. Once the needle moves past the middle point, check the lower rad hose if it is warm (lower right corner when standing in front of the car). If it is cold, replace the thermostat. If it is as hot as the upper rad hose... replace the fan switch.
@@EXOVCDS yes I've let it warm up well passed 20 min marker, needle never goes passed the middle mark . Rad hose lower is cold still and fans are not coming on .
It has been intermittently triggering the 2181 and p0172.
So even though not overheating it could be the thermostat correct ?
@@EXOVCDS are you still working in the lower mainland ?
After looking for the fix for this under my hood I've noticed green coolant in my car. It's used and 300k + on the odometer. But should that concern me to flush it and change it?
No. A bad thermostat will cause overheating. Hold engine rpm at 2000 for 10 minutes. Fans will either come on or the needle will go higher.
I'm confused. How did you get the fans to turn on after you disconnected them to test power?
As can be seen at 1:05, I used a metal paper clip / wire to bridge the "power" with the "load" (fan) side.
He didn't disconnect the power to the fan. He disconnected the plug from the temperature switch that tells the fans/fan control module to turn on low speed or high speed.
Thank you for the clarification ... I always assume that people pay attention to what I am doing in my videos. Actual fan harness plugs look different to the one I was bridging... and I don't recall mentioning to disconnect the fan. Thank you for paying attention to what I was doing! =)
My fans are not spinning at all, but car isn’t overheating🤔
Year, make, model, engine... AC?
@@EXOVCDS golf mk4 1.9 tdi 2000. AC works, but its not thst cold.
Do the fans spin when the AC is on?
TDI engines are very efficient / have little combustion heat left over... that is why they take a long time to heat up, to the point where radiator fans are needed. If the fans come on when AC is on, then everything is OK. To trigger the fans from engine heat... hold the engine rpm at 2000 - 2500. It may take 15 to 20 minutes before the fans come on. When you let the engine idle, there's not enough heat, so the fans are not needed.
@@EXOVCDS even when the AC is on fans not spinning. High and low AC still not spinning… Ive been driving for a while and then stop to look if fans are working and they not.
Thank you for the answers! I appreciate that :)
Most likely the fans burnt out. As soon as you start driving, the radiator is cooled... tdi engines take a long time to heat up. Hold the rpm at 2000 for 10 to 20 minutes... temperature will go past the middle if the fans don't come on. Replace the fans and your ac will blow colder.
Are you from Alberta? You're accent sounds like Jordan Peterson, must be a regional dialect.
German guy... living in BC.
@@EXOVCDS
Yeah, bigger regions in Canada to begin with. My radiator fan (MK4 2005 Jetta) kept going until battery died last night. Today I removed the green fuse just to stop it from spinning. I bet I can't just keep driving with that fuse out forever though, eh? Thanks for all the vids and how specific they are..
At what speed was it spinning? Low or high speed? AC or no AC?
@@EXOVCDS
When I had the battery connected, it was running. No stopping it when battery leads were attached. And I don't think it was high, I think high is noticeably louder. How would I tell low vs. high? I can plus the green fuse, and red fuse back in and see (both are unattached right now). I did get a coolant sensor reading the last time we hooked the car up to a computer (3 weeks ago or so). Right now I have the red fuse line and green fuse unattached & removed, which feed the radiator/coolant fan just so I can use my car, and keep from the battery getting drained.
@@EXOVCDS
I'll check if AC is working with fuses attached back on again for a minute, since you make it sound like AC is related...
Qaudi
?