Performing a voltage drop test on the starting system. This will prevent mistakenly replacing a starter when the problem was a bad cable or connection.
I liked this video because it emphasized the positive and negative side of the circuits/cables, and gave one test for each. From these tests, it's easy to 'back into' isolating either starter or the soleinoid as the main source of voltage drop. I have a 50 year old 'muscle car,' but the principles are the same as with the 2007 Chevy.
Good video. An easier way to do this (so you only go under car once) is to measure voltage from the starter itself at the positive and negative while cranking. Take note of the reading. Then take a reading from the battery itself from the posts while cranking. Subtract your starter reading from this reading and the difference is the voltage drop in the wiring. The only disadvantage is if you do have voltage drop that is out of spec, you cannot differentiate whether it is from + or - side so in that case your method would need to be employed (but only on one side of the circuit, actually).
Schrodingers Box, we can clearly see the maximum voltage drop in both cases is higher when overcoming the inertia. Which value should we take into consideration the most? The maximum drop or the drop afterwards?
Mr. Obvious : I bought a car at an auction that had been sitting and the battery was discharged . It was for parts . When the tow guy went to start it and it barely cranked , he stated " you need an alternator " . No testing - he should be " telling fortunes " on the side . If these idiots actually believe this - they are dangerous !
hey schrodingers maybe you can help me on a few easy questions as a diy guy and because we cant do voltage drop without current to test the wire and many times a no crank has no current flow i would like an opinion on using jumper cables as a way to determine bad cables meaning if i have a no crank yet have power and ground but when i hook a jumper cable from battery to positive/negitive to starter pos/neg (one at a time to determine which side has resistance)and it then starts i can then confirm high resistance in the cable.is this a viable method? also i hear we cant just create a circuit using a light in the starter circuit to create a loaded circuit we can voltage drop test because the light doesnt pull enough amps,but if the voltage drop is enough to prevent a starter from starting wouldnt this method still see the voltage drop? also any other methods for diyers to perform a voltage drop test on a circuit that doesnt have current flow?
When doing the positive side , it's important to connect to the top POST on the solenoid . Do NOT connect to the metal cable end or TAB . If there is a problem with the cable , it could skew the reading .
This procedure tests cables. To test the battery, measure across the battery terminals for the lowest reading while cranking. In this video, the voltmeter has a min or max reading function, and that is very convenient for finding the lowest voltage while cranking.
Awesome video!. I have to do a Practical of this exact test for level 1 auto technician training, my book actually saying to hook up the leads the other way, but clearly wrong🙄
Depending where you do the positive side test, you also know the starter relay is making good contact. Over time relay connections can become pock marked and burnt, due to spark each time starter throwout relay engages it. Basically its switch contacts with large current, so each time it engages its as if the contacts are momentarily an arc welder. Over time these contacts can become so abused they no longer make good contact. This test would detect that. You could isolate to starter relay by comparing the voltage drop when testing to starter relay input vs starter relay output. If low drop going between battery and relay in, but high drop battery to relay out, bad starter relay.
Good vid! Is 0.5v on the positive side, and 0.2v on the negative side, pretty consistent on most vehicles, or does this change for different applications? Im having a starter issue on a boat that i just purchased. It has an inline 6 GM motor. It has a dead battery and a dead starter. I swapped out the starter for a used starter that i had on my shelf, and this starter wont turn engine over either...i dont have another good battery at the moment. Is it ok that i perform this test while hooking my battery charger up to the bad battery? It is a large one with 2A, 20A, 40A, and start feature.
On the starter where you hooked the negative meter lead, you referred to that as the B terminal. Is that other end of the red cable from the positive post of the battery connected to the starter? In other words, the positive meter lead is connected to one end of the red cable at the battery and the negative lead from the meter is connected to the other end of the same cable at the starter?
I belive i have drop voltage from battery to fuel pump (positive side) 12,6 volts in battery, when i turn on fuel pump it drops to 0.4 Volts, is that normal or should the fuel pump voltage be the same as battery when turned on?
Good video but could have just got right to it. Red to this, black to this, test, results, ect. Again good video and appreciate the time you took to make it. 🤙🏻
as a diy guy and because we cant do voltage drop without current to test the wire and many times a no crank has no current flow i would like an opinion on using jumper cables as a way to determine bad cables meaning if i have a no crank yet have power and ground but when i hook a jumper cable from battery to positive/negitive to starter pos/neg (one at a time to determine which side has resistance)and it then starts i can then confirm high resistance in the cable.is this a viable method? also i hear we cant just create a circuit using a light in the starter circuit to create a loaded circuit we can voltage drop test because the light doesnt pull enough amps,but if the voltage drop is enough to prevent a starter from starting wouldnt this method still see the voltage drop? also any other methods for diyers to perform a voltage drop test on a circuit that doesnt have current flow?
I know you didn't ask me, but I'll share my thoughts. The jumper cable deal, I've used this method many times it's quick and easy. It's always a good idea to verify a circuit can carry a load, a starter can pull 100-200amps when cranking and a test light will probably pull half an amp(ish). Imagine a partially clogged water line, when you turn the sink on (test light) it flows fine and you think all is well. But when you turn the sink on, start washing clothes, and running a bath (starter) it suddenly becomes a trickle. Imagine resistance as a clog. The circuit may be able to provide enough current to illuminate the test light but not enough to power the starter. I would try to load test a circuit with something that pulls a similar amount of amps
I’m going to use this procedure on my wife’s 1999 Chevrolet Suburban to do a voltage drop test on the starting circuit. What was the other lead of the remote starter switch attached to? I know one goes to the “s” terminal on the solenoid where on the battery cable is the other lead attached to?
You connect the other lead to the top post of the solenoid where the battery cable goes . It's like jumping between the top post and S terminal . Just like the ignition switch does when turned to START .
No! It is hard on the coil packs as they can spark internally. Two exceptions: 1) ground every HT lead at the plug end, or 2) if you have an older car with a distributor, then you can disconnect the coil to distributor HT lead at the distributor, then ground it so the spark has a clean path to ground. With a modern car, rather than disconnect the HT, pull the fuel pump fuse so you can crank without starting the car.
A volt meter measures voltage BETWEEN the black and red probes. So if you get a voltage drop from the + batt post to the + batt connector, you have a poor connection at that post. Then you test on down the + and - lines to and from the starter. This is a valuable testing procedure to see if your starter or battery cables are at fault.
You need to shoot for a 3% voltage drop. Add the drop from BOTH + and - sides, combined together as he did in this video. Combined you should not have more than a 3% drop.
Yes. That applies to any electrical circuit. If you want to test a ground connection where you can't just look at voltage in a normal way because there is none on the ground side of a circuit, a voltage drop test will do the trick.
Why would you go pos to pos and neg to neg as oppose to placing the probes conventionally? I.e; Pos probe to battery pos and neg probe to bell housing/gear box earth point. Crank over and if a bad earth is present you would have 12v minus your resistance/bad earth bringing you down to say 10v for example. Same on the pos side, probe to solenoid probe and neg probe to battery neg. This was is easier to process in your mind as you can clearly see the voltage drop compared to the 12 volts you would have just before cranking. Its easier to comprehend for the average Joe. Your way does give the exact figure of the voltage drop but I think it would confuse people who aren't professional tech.
+Ben Harris A volt meter measures voltage BETWEEN the black and red probes. So if you get a voltage drop from the + batt post to the + batt connector, you have a poor connection at that post. Then you test on down the + and - lines.
I have one where the Battery reads 12.5v with the key out. Cranking, The Battery Positive Terminal drops to 10.9v and at the Starter Positive it reads 9.8v to 10.2v ... What are your thoughts ? Bad Positive Starter Cable , Bad Ground, ( It Looks to be a New Starter and New Alternator with a Reconstruct Title) Starter Over Drawing Amperage , etc... That's a pretty big drop. I have only looked at it really quick , late at night, in rain and snow, when I saw a hood popped at the neighbor's house... . I'm going to go back with more than just my Power Probe... lol.. Damn, I do Love The Power Probe... In anycase, would love to hear your views... I just stumbled across your channel and it is Excellent... Presentation , Clear Speech and Communications, Great Analogies , Straight Forward, I could go on... but no combination of words would do you justice... I'm Sunscribing and going to see what else you offer. Thank You for Your Time and Effort. You Truly Are Helping People and Educating Them...
I know this is going to seem like a stupid question but all you're doing is trying to find out if you're having good continuity to your starter on the positive side and the ground with this test so why couldn't you test the starter wire with a analog load tester and just load the starter wire we should get the same results as having it attached to the battery
Hi did this test on my bike starter as it won't start and seems to be turning over slow, reading on positive side was .144 and on negative was .166 which I thought a bit much, all connections are tight, would my starter be on it's way out???
Hey Martyn, did you find out what the problem with your bike starter was? I'm having a problem with my Harley starter stalling on the compression stroke and not turning the engine over. I replaced a bunch of parts, including the starter, but still not have had any luck finding the problem. I'm sure the only thing left it could be is a wiring problem but I don't know which wire. I'm going to try doing this voltage drop testing to see if I can figure out the problem.
Would it not be a whole lot easier to use a loadpro tester? No remote starter hookup, no spinning parts, no going back and forth to make connections?Just check the connector at the starter motor. Push the button to load the circuit and you have your results. You don't have to worry that your ground connection on the housing is throwing your results off either. I like to save time so I can get back to telling stories, joking, drinking, gambling and chasing women.
I don't like your saying connect voltmeter leads to positive terminal of battery and to "most negative part of the positive cable going to the starter". Would be good to say where the positive cable connects to starter. and after you connected the positive end of the voltmeter to the positive battery terminal you say you will connect the negative side of the voltmeter to the starter while the important idea is you re going to connect the negative side of the voltmeter to the positive cable at point of connects to starter. So we learn the cables from battery to starter and from starter to ground are good. how many volts on a weak battery will be enough to power the starter and crank the engine?
Most all modern cars have a starter relay , at the relay use a jumper wire in the secondary terminals with key off . No need of remote starter switch. and ignition and fuel systems will not be energized while performing test .
It's remote from the ignition system. The ignition system would be off and he's instead (manually) enabled to complete the starter circuit. All with no actual power through the ignition key.
I have one where the Battery reads 12.5v with the key out. Cranking, The Battery Positive Terminal drops to 10.9v and at the Starter Positive it reads 9.8v to 10.2v ... What are your thoughts ? Bad Positive Starter Cable , Bad Ground, ( It Looks to be a New Starter and New Alternator with a Reconstruct Title) Starter Over Drawing Amperage , etc... That's a pretty big drop.
It all starts at the battery terminal (+ lead) to the battery terminal connector (- lead) ON the battery. Write the drop down. Next is batt term connector to opposite connector directly. Write the drop down. Then last connector to starter terminal, write the drop down. Add all the drops up. That way you test every connection separately and KNOW where the failure is directly. Yes you can probe the + batt terminal and starter lug for the total drop UNDER CRANKING LOAD. You won't find the issue if you have one done that way. The long way identifies corrosion drops, loose batt terminal/s drop and so on.
I liked this video because it emphasized the positive and negative side of the circuits/cables, and gave one test for each. From these tests, it's easy to 'back into' isolating either starter or the soleinoid as the main source of voltage drop. I have a 50 year old 'muscle car,' but the principles are the same as with the 2007 Chevy.
Just finished watching your voltage drop test on alternator and starter. Good video!
Good video. An easier way to do this (so you only go under car once) is to measure voltage from the starter itself at the positive and negative while cranking. Take note of the reading. Then take a reading from the battery itself from the posts while cranking. Subtract your starter reading from this reading and the difference is the voltage drop in the wiring.
The only disadvantage is if you do have voltage drop that is out of spec, you cannot differentiate whether it is from + or - side so in that case your method would need to be employed (but only on one side of the circuit, actually).
+Schrodingers Box Yes and no. A voltage drop test allows you to SEE where the problem is if you have one. You test every connector and wire both ways.
Schrodingers Box, we can clearly see the maximum voltage drop in both cases is higher when overcoming the inertia. Which value should we take into consideration the most? The maximum drop or the drop afterwards?
Mr. Obvious : I bought a car at an auction that had been sitting and the battery was discharged . It was for parts . When the tow guy went to start it and it barely cranked , he stated " you need an alternator " . No testing - he should be " telling fortunes " on the side . If these idiots actually believe this - they are dangerous !
hey schrodingers maybe you can help me on a few easy questions
as a diy guy and because we cant do voltage drop without current to test the wire and many times a no crank has no current flow i would like an opinion on using jumper cables as a way to determine bad cables meaning if i have a no crank yet have power and ground but when i hook a jumper cable from battery to positive/negitive to starter pos/neg (one at a time to determine which side has resistance)and it then starts i can then confirm high resistance in the cable.is this a viable method?
also i hear we cant just create a circuit using a light in the starter circuit to create a loaded circuit we can voltage drop test
because the light doesnt pull enough amps,but if the voltage drop is enough to prevent a starter from starting wouldnt this method still see the voltage drop?
also any other methods for diyers to perform a voltage drop test on a circuit that doesnt have current flow?
When doing the positive side , it's important to connect to the top POST on the solenoid . Do NOT connect to the metal cable end or TAB . If there is a problem with the cable , it could skew the reading .
this really helped me understand! if you can make any more videos about voltage drop that would be much appreciated! thanks
Thank you for this excellent video
This procedure tests cables. To test the battery, measure across the battery terminals for the lowest reading while cranking. In this video, the voltmeter has a min or max reading function, and that is very convenient for finding the lowest voltage while cranking.
Very well explained!
Best video I have seen explaining how to do this.. THANK YOU!
Nice Video, I tried it on my jeep and ran my foot over. Next time I'll put it in neutral.
Rich Furber is this test for testing the the starting systems circuit or the starter itself?
Great tutorial thanks 👍
From Nick Ayivor from London England UK 🇬🇧
Awesome video!. I have to do a Practical of this exact test for level 1 auto technician training, my book actually saying to hook up the leads the other way, but clearly wrong🙄
That was great advice .thanks
Rick : Agreed . If you test everything , than nothing is left to chance .
Depending where you do the positive side test, you also know the starter relay is making good contact. Over time relay connections can become pock marked and burnt, due to spark each time starter throwout relay engages it. Basically its switch contacts with large current, so each time it engages its as if the contacts are momentarily an arc welder. Over time these contacts can become so abused they no longer make good contact. This test would detect that.
You could isolate to starter relay by comparing the voltage drop when testing to starter relay input vs starter relay output. If low drop going between battery and relay in, but high drop battery to relay out, bad starter relay.
Where did the specs for the .5v drop and .2v drop come from? Are those generally universal? Or specific to the starter?
Please explain Solenoid hook up, my Chevy 2500hd only has hot and other small wire on it.
Good vid!
Is 0.5v on the positive side, and 0.2v on the negative side, pretty consistent on most vehicles, or does this change for different applications?
Im having a starter issue on a boat that i just purchased. It has an inline 6 GM motor. It has a dead battery and a dead starter. I swapped out the starter for a used starter that i had on my shelf, and this starter wont turn engine over either...i dont have another good battery at the moment. Is it ok that i perform this test while hooking my battery charger up to the bad battery? It is a large one with 2A, 20A, 40A, and start feature.
Great video bud, would I expect the same results with a starter that was struggling to turn? Thanks
Good job!!!!
On the starter where you hooked the negative meter lead, you referred to that as the B terminal. Is that other end of the red cable from the positive post of the battery connected to the starter? In other words, the positive meter lead is connected to one end of the red cable at the battery and the negative lead from the meter is connected to the other end of the same cable at the starter?
How was the remote trigger connected up and how did it have 12v to start with ?
was it just connected to the battery in the car or another battery ?
Excellent!
Good video
I belive i have drop voltage from battery to fuel pump (positive side) 12,6 volts in battery, when i turn on fuel pump it drops to 0.4 Volts, is that normal or should the fuel pump voltage be the same as battery when turned on?
Well done. Just subscribed to ur channel.
Good video but could have just got right to it. Red to this, black to this, test, results, ect.
Again good video and appreciate the time you took to make it. 🤙🏻
Good video, you should have just mentioned what the meter would read if the wires were bad!
as a diy guy and because we cant do voltage drop without current to test the wire and many times a no crank has no current flow i would like an opinion on using jumper cables as a way to determine bad cables meaning if i have a no crank yet have power and ground but when i hook a jumper cable from battery to positive/negitive to starter pos/neg (one at a time to determine which side has resistance)and it then starts i can then confirm high resistance in the cable.is this a viable method?
also i hear we cant just create a circuit using a light in the starter circuit to create a loaded circuit we can voltage drop test
because the light doesnt pull enough amps,but if the voltage drop is enough to prevent a starter from starting wouldnt this method still see the voltage drop?
also any other methods for diyers to perform a voltage drop test on a circuit that doesnt have current flow?
I know you didn't ask me, but I'll share my thoughts. The jumper cable deal, I've used this method many times it's quick and easy.
It's always a good idea to verify a circuit can carry a load, a starter can pull 100-200amps when cranking and a test light will probably pull half an amp(ish).
Imagine a partially clogged water line, when you turn the sink on (test light) it flows fine and you think all is well.
But when you turn the sink on, start washing clothes, and running a bath (starter) it suddenly becomes a trickle.
Imagine resistance as a clog. The circuit may be able to provide enough current to illuminate the test light but not enough to power the starter.
I would try to load test a circuit with something that pulls a similar amount of amps
I’m going to use this procedure on my wife’s 1999 Chevrolet Suburban to do a voltage drop test on the starting circuit. What was the other lead of the remote starter switch attached to? I know one goes to the “s” terminal on the solenoid where on the battery cable is the other lead attached to?
You connect the other lead to the top post of the solenoid where the battery cable goes . It's like jumping between the top post and S terminal . Just like the ignition switch does when turned to START .
would disconnecting the HT leads be an ok of preventing the engine from starting
No! It is hard on the coil packs as they can spark internally. Two exceptions: 1) ground every HT lead at the plug end, or 2) if you have an older car with a distributor, then you can disconnect the coil to distributor HT lead at the distributor, then ground it so the spark has a clean path to ground. With a modern car, rather than disconnect the HT, pull the fuel pump fuse so you can crank without starting the car.
How to disable the starting system? Thank you
A volt meter measures voltage BETWEEN the black and red probes. So if
you get a voltage drop from the + batt post to the + batt connector, you
have a poor connection at that post. Then you test on down the + and -
lines to and from the starter. This is a valuable testing procedure to see if your starter or battery cables are at fault.
what if the starter isn't cranking over will this test still be helpful?
No, There has to be current flow for an accurate reading.
You need to shoot for a 3% voltage drop. Add the drop from BOTH + and - sides, combined together as he did in this video. Combined you should not have more than a 3% drop.
What about when starters are buried under a intake manifold like on a nissan titan ?
Jesse Lyons buy a real car
Thanks...
So if you connect negative from the battery and connect the other lead to negative of the load, you can measure voltage drop?
Yes. That applies to any electrical circuit. If you want to test a ground connection where you can't just look at voltage in a normal way because there is none on the ground side of a circuit, a voltage drop test will do the trick.
Awesome didn't k ow that. Thank for sharing great tip
It's called DIRECT voltage drop
Nice vid. How about the crank voltage?.
Thanks. 😊
Suf what start slow clicking noise was stuk in park
Why would you go pos to pos and neg to neg as oppose to placing the probes conventionally? I.e; Pos probe to battery pos and neg probe to bell housing/gear box earth point. Crank over and if a bad earth is present you would have 12v minus your resistance/bad earth bringing you down to say 10v for example. Same on the pos side, probe to solenoid probe and neg probe to battery neg. This was is easier to process in your mind as you can clearly see the voltage drop compared to the 12 volts you would have just before cranking. Its easier to comprehend for the average Joe. Your way does give the exact figure of the voltage drop but I think it would confuse people who aren't professional tech.
+Ben Harris A volt meter measures voltage BETWEEN the black and red probes. So if you get a voltage drop from the + batt post to the + batt connector, you have a poor connection at that post. Then you test on down the + and - lines.
I have one where the Battery reads 12.5v with the key out.
Cranking, The Battery Positive Terminal drops to 10.9v and at the Starter Positive it reads 9.8v to 10.2v ...
What are your thoughts ? Bad Positive Starter Cable , Bad Ground, ( It Looks to be a New Starter and New Alternator with a Reconstruct Title) Starter Over Drawing Amperage , etc...
That's a pretty big drop.
I have only looked at it really quick , late at night, in rain and snow, when I saw a hood popped at the neighbor's house... .
I'm going to go back with more than just my Power Probe... lol.. Damn, I do Love The Power Probe...
In anycase, would love to hear your views... I just stumbled across your channel and it is Excellent... Presentation , Clear Speech and Communications, Great Analogies , Straight Forward, I could go on... but no combination of words would do you justice... I'm Sunscribing and going to see what else you offer.
Thank You for Your Time and Effort. You Truly Are Helping People and Educating Them...
Bad cabel
I know this is going to seem like a stupid question but all you're doing is trying to find out if you're having good continuity to your starter on the positive side and the ground with this test so why couldn't you test the starter wire with a analog load tester and just load the starter wire we should get the same results as having it attached to the battery
How did you basically set up the starting trigger/button?
You put one on the positive battery terminal and then other on the S terminal of the starter, it'll be the smallest terminal on the housing
How long are your Meter leads? LOL With the shorty leads of most generic MMs you wouldn't be reaching any starter from up there.
how did you hook up the remote starter again? I get that it goes to the s terminal but how is the trigger powered?
Positive battery terminal.
Hi did this test on my bike starter as it won't start and seems to be turning over slow, reading on positive side was .144 and on negative was .166 which I thought a bit much, all connections are tight, would my starter be on it's way out???
Hey Martyn, did you find out what the problem with your bike starter was? I'm having a problem with my Harley starter stalling on the compression stroke and not turning the engine over. I replaced a bunch of parts, including the starter, but still not have had any luck finding the problem. I'm sure the only thing left it could be is a wiring problem but I don't know which wire. I'm going to try doing this voltage drop testing to see if I can figure out the problem.
Would it not be a whole lot easier to use a loadpro tester? No remote starter hookup, no spinning parts, no going back and forth to make connections?Just check the connector at the starter motor. Push the button to load the circuit and you have your results. You don't have to worry that your ground connection on the housing is throwing your results off either. I like to save time so I can get back to telling stories, joking, drinking, gambling and chasing women.
That’s exactly what I was thinking.
LoadPro by Dan Sullivan is a time saver.
I don't like your saying connect voltmeter leads to positive terminal of battery and to "most negative part of the positive cable going to the starter". Would be good to say where the positive cable connects to starter. and after you connected the positive end of the voltmeter to the positive battery terminal you say you will connect the negative side of the voltmeter to the starter while the important idea is you re going to connect the negative side of the voltmeter to the positive cable at point of connects to starter. So we learn the cables from battery to starter and from starter to ground are good. how many volts on a weak battery will be enough to power the starter and crank the engine?
Thanks
Most all modern cars have a starter relay , at the relay use a jumper wire in the secondary terminals with key off . No need of remote starter switch. and ignition and fuel systems will not be energized while performing test .
No...most ALL cars do not have starter relays.. some do
Did you disabled the ignition system ? Or did you just hooked up the remote starter switch?
It's remote from the ignition system. The ignition system would be off and he's instead (manually) enabled to complete the starter circuit. All with no actual power through the ignition key.
My voltage drop on the positive side is 1.5v
That means my starter is bad, right?
I would start with the battery cable that runs to the positive on the solenoid.
I have one where the Battery reads 12.5v with the key out.
Cranking, The Battery Positive Terminal drops to 10.9v and at the Starter Positive it reads 9.8v to 10.2v ...
What are your thoughts ? Bad Positive Starter Cable , Bad Ground, ( It Looks to be a New Starter and New Alternator with a Reconstruct Title) Starter Over Drawing Amperage , etc...
That's a pretty big drop.
no offense meant, but you could easily cut 3 minutes out of this video and lose nothing. Good info, thanks.
no shit all of them are like that they talk too much
if the key is off and you use the remote then it isnt going to start. you dont have to unhook anything
**FORGET IT** can't you hear that by that starter sound, ALL is well?? present us some failure instead.
if 0.5 is 1/2 a volt, what is 1/2 of 0.5 considered or called?
.25v or a quarter of a volt?
how would all figures read including decimal and zeros?
jaeden amaral
one volt: 1 volt: 1.00V
half a volt: 1/2 volt: 0.50V
quarter of a volt: 1/4 volt: 0.25V
Cool buddy, thank you.
Does the zero always show on 1/2 a volt......say it only reads 0.5 it's still considered 1/2 a volt?
I hate sophistication techniques.. they make me mental. Awesome video though -
Poor lighting at the starter
Too much yapping, could have been more concise
Learn how to explain man. U put red lead on + battery people , then the - lead on the nut that has the battery cable connected to it.
+Headshothorror4488 It's called the battery post to battery connector.
jim davidson lol yeah I didn't do so great explaining either
We ALL learn something everyday LOL
It all starts at the battery terminal (+ lead) to the battery terminal connector (- lead) ON the battery. Write the drop down. Next is batt term connector to opposite connector directly. Write the drop down. Then last connector to starter terminal, write the drop down. Add all the drops up. That way you test every connection separately and KNOW where the failure is directly. Yes you can probe the + batt terminal and starter lug for the total drop UNDER CRANKING LOAD. You won't find the issue if you have one done that way. The long way identifies corrosion drops, loose batt terminal/s drop and so on.
Over 9 minutes! Too much talking.