Wrong temp sensor on a dodge will cause over rich condition or very lean. It's also the first sensor that the PCM looks at during cranking. Had a friend that works at Orieley's through everything at his 99 RAM. Even PCM. I asked to take a look at it. first code temp sensor reading -40 deg. replaced sensor and connector now truck runs great and doesn't fowl the plugs. Put his old PCM back and now it shifts all the gears also. simple 20.00 dollar fix. A simple code reader with data function will save you a lot of money in the long run. In this case they had the scanner but just didn't use it correctly.
Dan, what I understand is that the sensor is essentially a thermistor. A thermistor will vary its resistance reading with a change in temperature. The computer (pcm) will issue a continual dc voltage to the sensor and read the resistance. The change in coolant temp continually changes the thermistors resistance and the pcm will report the temp to the guage. Somewhere there should be a chart that shows the relationship between resistance and temperature for Dodge coolant sensors. If you can find that, you can immerse the sensor into a container of water along with a digital thermometer. When you read accurately the water temp, you should then read the corresponding resistance on the chart for that temperature with an accurate digital ohm meter across the two pins on the sensor. I don't guarantee that is totally accurate information for your vehicle but that's the routine we go through in sensor testing in commercial HVAC equipment and building automation controls. A LOT of our sensors read 10,000 ohms at 77 degree Fahrenheit. I'm sure automotive is different.
Buy OEM sensors whenever possible or from known OEM Mfgr. Some sensors can test in tolerance but be off by a tenth of a volt and cause issues. O2 sensors are probably the worst for it.
I had a similar problem with my 98. The part I got from Autozone wouldn't screw in. The threaded part was slightly too large. I got an OReilly one to work. Could be expansion over time crunched the old one since its just brass but it was a pain getting a new one that fit.
From what I know of either my rams and jeep water sensor gets signal from PCM. Pcm controls accual temp . Dodges are messed up with parts my 1 truck uses like 5 different radiators just a example of dodge's crazy engineer.
Wrong temp sensor on a dodge will cause over rich condition or very lean. It's also the first sensor that the PCM looks at during cranking. Had a friend that works at Orieley's through everything at his 99 RAM. Even PCM. I asked to take a look at it. first code temp sensor reading -40 deg. replaced sensor and connector now truck runs great and doesn't fowl the plugs. Put his old PCM back and now it shifts all the gears also. simple 20.00 dollar fix. A simple code reader with data function will save you a lot of money in the long run. In this case they had the scanner but just didn't use it correctly.
Dan, what I understand is that the sensor is essentially a thermistor. A thermistor will vary its resistance reading with a change in temperature. The computer (pcm) will issue a continual dc voltage to the sensor and read the resistance. The change in coolant temp continually changes the thermistors resistance and the pcm will report the temp to the guage.
Somewhere there should be a chart that shows the relationship between resistance and temperature for Dodge coolant sensors. If you can find that, you can immerse the sensor into a container of water along with a digital thermometer. When you read accurately the water temp, you should then read the corresponding resistance on the chart for that temperature with an accurate digital ohm meter across the two pins on the sensor.
I don't guarantee that is totally accurate information for your vehicle but that's the routine we go through in sensor testing in commercial HVAC equipment and building automation controls. A LOT of our sensors read 10,000 ohms at 77 degree Fahrenheit. I'm sure automotive is different.
Thanks , Just Uploaded a Update.
Buy OEM sensors whenever possible or from known OEM Mfgr. Some sensors can test in tolerance but be off by a tenth of a volt and cause issues. O2 sensors are probably the worst for it.
That's very different looking hopefully is works better than the old one
I had a similar problem with my 98. The part I got from Autozone wouldn't screw in. The threaded part was slightly too large. I got an OReilly one to work. Could be expansion over time crunched the old one since its just brass but it was a pain getting a new one that fit.
Good luck Dan, hope it is your problem
if you have a ohm meter you can take a reading on both and see if there close or 1 is way off.
Fighting this same issue pretty much changed the one on the back of the head and the gauge still won't work accurately
There is no temp sensor on the back of the head...there is a oil sensor guage sensor tho
What's the update on this? Did it ever work???
From what I know of either my rams and jeep water sensor gets signal from PCM. Pcm controls accual temp . Dodges are messed up with parts my 1 truck uses like 5 different radiators just a example of dodge's crazy engineer.