Glad you take the time to explain voltage drop to people. Most important concept a mechanic needs to understand IMO. Once you get it, it seems simplistic but understanding how to use it to figure out problems takes time for folks to wrap their minds around.
Skip the scope and stay with the meter. It's what most will have. Make sure to use the battery POST when testing as the clamp and everything else is part of the circuit. Interesting thing to do when you get a new car into the shop is test the ground side straight away KOEO and KOER with as many loads operating as possible. Neg probe on neg term and float around the pos probe on various metal point on chassis, frame and engine. You need clean bright metal when landing your probes.
Great video. Unfortunately in this situation if they replaced the starter it would probably fix it. They would probably take the negative terminal off (to replace the starter) and when they put it back on they would notice it didn’t have a bolt. Some techs might not even have known the starter was good. That is why it is important to teach things like this. Great video.
the video is wonderful the only point that i see that can be improved on when you were showing scope we didn't know which color represented what information as far as voltage we could see things on scope move but couldn't read what they meant i personally think the meter with the led readout is a better visual aid for videos. just my 2cents worth.
Hey great explanation. It makes a lot of sense when you apply on a bench test to an actual vehicle test it makes it much clearer. As you mention sometimes batteries are well hidden. Can you perform a voltage drop from boosting point. If you measured across the boosting pole would you read 8 volts (voltage drop) just try to understand a bit better. I agree with you 100% you can not be lazy because you may get burnt and go in a rabbit hole and chase things that are not an issue. I try to keep it simple but not be lazy to do research and perform test to get the right diagnosis. Thanks for all your explanations you are a game changer in this difficult industry
Thanks! I really appreciate it!! As far as the jump post, the only way you could use it would be to test from it to the battery first and be sure the circuit is good. But, at that point, you're at the battery. I know it sucks but you gotta do it.
Teaching voltage drop using test boards and diagrams on paper or whiteboards is certainly useful, but real world examples are invaluable. This is an excellent illustration of why it's so important to ground directly to the negative battery post. You can easily have zero voltage drop between two "bad" grounds. This is why I keep a ten foot long jumper wire, so that I can always reach the negative battery post from anywhere else on the car. Far too many automotive technicians simply unload the "parts cannon" until the problem disappears, never really understanding what the problem really was, and costing their customers far too much money. Well done, Sherwood!
Watched part 1 and 2, best volatge drop explation on internet. Could you explain how to diagnosis relays and solenoide problems from your point of view as well
Helow sir, i like ur channel. I just subscribe. the only thing I just recommend you to use a mic because when you working inside, it’s a little hard to hear Specially for someone who is English second language, but when you work outside, it’s loud and clear. thank you for ur help.
In the first demonstration with the meter, between the post and cable connector (with 8.44v drop), what was the load at that time, because he wasn't trying to start it. Is that from other things on the car drawing a current creating the load needed to test? Thanks
On a pervious job we had to do voltage drops on ign switches starter solenoids body to chassis alternator to battery and cranking we were allowed .1tenth a connection up to .6 tenths
I would agree with that. On larger load circuits, like a starter, you can have a larger voltage drop and still be ok. As long as it's within specs. Smaller load circuits can be as little as .5 volts or even less depending on the circuit. Thanks!
I'd have to re-watch the video buy all voltage drop testing should be done with the circuit loaded. Meaning if it's the starter circuit you would need to have the key in the crank position. If it's, let's say, a fuel pump circuit then you would need the pump circuit on. Hope this helps.
GREAT VIDEO LOVING IT, JUST A THOUGHT WHEN THIS SERIES IS FINISHED HOW ABOUT A VIDEO ON HOW TO TEST PARKING SENSORS REALLY GETTING MY ASS KICKED TRYING TO DIAGNOSE A 2020 NISSAN TITAN THANKS.
My only comment would be that I know nothing about a scope, so all the visual shots of the scope show me nothing. I understand what you're saying but showing me on the multimeter instead of the scope would visually show me better.
If you mean we would have had some drop then you are correct. But, it would have been very small and within spec. The problem was on the negative side.
Glad you take the time to explain voltage drop to people. Most important concept a mechanic needs to understand IMO. Once you get it, it seems simplistic but understanding how to use it to figure out problems takes time for folks to wrap their minds around.
Danner's hose analogy and your hill analogy
Was like first time wearing eye glasses
🤸🎉
Skip the scope and stay with the meter. It's what most will have. Make sure to use the battery POST when testing as the clamp and everything else is part of the circuit. Interesting thing to do when you get a new car into the shop is test the ground side straight away KOEO and KOER with as many loads operating as possible. Neg probe on neg term and float around the pos probe on various metal point on chassis, frame and engine. You need clean bright metal when landing your probes.
Great video. Unfortunately in this situation if they replaced the starter it would probably fix it. They would probably take the negative terminal off (to replace the starter) and when they put it back on they would notice it didn’t have a bolt. Some techs might not even have known the starter was good. That is why it is important to teach things like this. Great video.
I would love to have some more class sessions on voltage drop testing
Great video
90% of customer concerns are sold with The DCA battery tester and voltage drop techniques
More you do it, easier it gets. You are right Mr. Sherwood, it fixes A LOT of cars.... AL H.
That example was genius 👏
Nicely done and explained!! Part 2 came fast!!
the video is wonderful the only point that i see that can be improved on when you were showing scope we didn't know which color represented what information as far as voltage we could see things on scope move but couldn't read what they meant i personally think the meter with the led readout is a better visual aid for videos. just my 2cents worth.
Hey great explanation. It makes a lot of sense when you apply on a bench test to an actual vehicle test it makes it much clearer. As you mention sometimes batteries are well hidden. Can you perform a voltage drop from boosting point. If you measured across the boosting pole would you read 8 volts (voltage drop) just try to understand a bit better. I agree with you 100% you can not be lazy because you may get burnt and go in a rabbit hole and chase things that are not an issue. I try to keep it simple but not be lazy to do research and perform test to get the right diagnosis. Thanks for all your explanations you are a game changer in this difficult industry
Thanks! I really appreciate it!! As far as the jump post, the only way you could use it would be to test from it to the battery first and be sure the circuit is good. But, at that point, you're at the battery. I know it sucks but you gotta do it.
Teaching voltage drop using test boards and diagrams on paper or whiteboards is certainly useful, but real world examples are invaluable. This is an excellent illustration of why it's so important to ground directly to the negative battery post. You can easily have zero voltage drop between two "bad" grounds. This is why I keep a ten foot long jumper wire, so that I can always reach the negative battery post from anywhere else on the car. Far too many automotive technicians simply unload the "parts cannon" until the problem disappears, never really understanding what the problem really was, and costing their customers far too much money. Well done, Sherwood!
Brilliant video well explained 🔥
Good stuff thanks for taking the time to do these
Nice knowledge, with simplicity.
Hello from France, excellent video, thanks so much
Thank you. Love your videos and appreciate how much effort you put in teaching.
Thanks alot fir taking your time to show us.. Very helpful. Great video. Cheers.
Thank you for sharing such great information
Appreciate these kinda of videos Mr Sherwood. Thanks
your on point now!👍
Watched part 1 and 2, best volatge drop explation on internet. Could you explain how to diagnosis relays and solenoide problems from your point of view as well
Helow sir, i like ur channel. I just subscribe. the only thing I just recommend you to use a mic because when you working inside, it’s a little hard to hear Specially for someone who is English second language, but when you work outside, it’s loud and clear. thank you for ur help.
We do use mics. Sometimes the noise in the shop still gets picked up by the mics. We will try to do better. Thanks for the suggestion and the sub!
You right. I keep watching ur videos just some of them only noise
Thanks again
Great work!
Good job👍 would that voltage drop show up on a thermal camera?
That much drop would definitely cause heat so I'd yes. I wish I would have brought it out and shown that! 😪 Next time. Thanks for the comment!!
Import point, thanks for sharing
Thanks for the video question fault code b1177 (abnormal battery voltage) should I be looking for voltage drops??. Thanks
In the first demonstration with the meter, between the post and cable connector (with 8.44v drop), what was the load at that time, because he wasn't trying to start it. Is that from other things on the car drawing a current creating the load needed to test?
Thanks
On a pervious job we had to do voltage drops on ign switches starter solenoids body to chassis alternator to battery and cranking we were allowed .1tenth a connection up to .6 tenths
I would agree with that. On larger load circuits, like a starter, you can have a larger voltage drop and still be ok. As long as it's within specs. Smaller load circuits can be as little as .5 volts or even less depending on the circuit. Thanks!
Vthank you very much for this informative video
Nicely explained
Ok you always have to do a physical inspection then I would do a voltage drop . Always go back to basics .
Great thank you sir
great video brotha ,thanks
pretty well explained👍👍👍👍
Most of the time when I mention and explain voltage drop to my clients they are like "moma said don't play with that voodoo."
very good
Is all of the testing in the first half of the video key on engine off?
I'd have to re-watch the video buy all voltage drop testing should be done with the circuit loaded. Meaning if it's the starter circuit you would need to have the key in the crank position. If it's, let's say, a fuel pump circuit then you would need the pump circuit on. Hope this helps.
GREAT VIDEO LOVING IT, JUST A THOUGHT WHEN THIS SERIES IS FINISHED HOW ABOUT A VIDEO ON HOW TO TEST PARKING SENSORS REALLY GETTING MY ASS KICKED TRYING TO DIAGNOSE A 2020 NISSAN TITAN THANKS.
Put your ear right up against them when they should be working you will hear a high pitched whine / clicking noise if it's ok
Watch out for the lead aftermarket battery terminal replacements.this situation happens a lot with those. Happy hunting down those drops, everyone.
Just as every brake inspection starts with the master cylinder, every electrical diag starts at the battery.
My only comment would be that I know nothing about a scope, so all the visual shots of the scope show me nothing. I understand what you're saying but showing me on the multimeter instead of the scope would visually show me better.
You would have had a voltage drop if you had cranked the engine when you put the meter on the positive post to the positive post of the starter.
If you mean we would have had some drop then you are correct. But, it would have been very small and within spec. The problem was on the negative side.
Still hills...