Voltage Drop, Do We Really Need To Know It!?

We always here about voltage drop in the classes we go to but does it ever really apply to fixing cars? It is always taught but never really shown in real life examples. Well any one who watches my channel knows I have shown in several videos why it is so important and how to use your meter to see the "pressure" difference between two points. Hear yet again is another example.

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Due to factors beyond the control of South Main Auto Repair, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. South Main Auto Repair assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. South Main Auto Repair recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of South Main Auto Repair, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained.

[nickmayo]

Also, my 6 year old son loves your videos, I'm glad you keep it family friendly :) "Is that what you do at your work Daddy?" "Yep, sure is bud".

[wyattoneable]

As basic as this seems it's still a great reminder of how to check for a voltage drop. There are guys like me who need to be reminded once in a while because we lack day to day experience. Thanks again for taking the time to teach.

[ianfahlman-morgan]

One of the best YouTube channels ever. I've been watching older videos back-to-back all afternoon 👍

[GeneralRELee]

Eric. O would make a awesome Auto Tech class instructor.

[kyhomegarage]

Thank you Eric for all time and effort you put in your channel. Truly outstanding work. Cheers👍

[HUBBABUBBADOOPYDOOP]

Be it a liquid, gas, photons or electrons- you can't find a leak until it's under pressure.

[CubasAutomotive]

You can definitely hear the difference in cranking after just cleaning the one terminal & cable.

[mykline]

Can't believe who ever put the new batteries in didn't clean the connections. Rule number one. Was taught that back in 1969 when going through mechanics school. You have to have clean connections throughout electrical systems.

[EvanT]

I'm in an automotive electrical fundamentals class in college right now and it's nice to see what we're learning being practiced on an actual vehicle! Thanks!!

Found a lot of problems over the years using voltage drop. Important to note that it will only show up when the circuit is under load. Once again, great video Eric. Thank you!

[chrisb]

Been a subscriber over a year, still can't believe you give this away. Thank you

[BigDaddy_MRI]

Just another outstanding video, Eric O. And, inside my head, the puzzle pieces make total sense. Thanks and please don’t stop. These videos are just like master mechanics classes. You da best!!!

[jkbrown]

Why run down a 200 mV voltage drop? Because at a modest 60 amp draw from the alternator that's 12 watts of heat on that battery post. 0.2v doesn't sound like much until you apply the current. That's like a 1 amp bulb feeding heat right into the battery plates.

[SmittySmithsonite]

Great demonstration here, Eric. A prime example of how voltage drop can affect any circuit. A high-amp draw circuit was the PERFECT example. What a difference in cranking RPM after ward! Could clearly hear the difference, even through the camera, across the internet, and through my speakers here. Was great to see the numbers vs. the cranking sound! 👍👍

My very first foray into this realm was with my aftermarket under-dash A/C system in my '72 El Camino, in the 110°F summer heat of Phoenix, AZ. The off/low/high switch I noticed was SUPER hot, when my finger got behind the Bakelite knob and touched the metal behind it. I could smell something burning, and the fans were real slow on high, too. Had a 5+ V drop across the switch! Wire connections were good, though - it needed a new switch (or, I could've disassembled it and cleaned inside it ... but it was all sloppy anyway). Installed the new one, and the fans blew stronger than ever. It's nice feeling 65° air when it's 114°F outside. 😁

[rockiemountin]

Best auto diagnostics channel on YouTube Thanks Eric👍

[davidduran]

Currently learning this in class. Was having a hard time understanding voltage drop but after watching your video, I have a way better understanding of how the test works. Love your videos and keep up the good work.

[Rockardo_]

I’m currently learning voltage drop at my training for my dealership and this is such a great way for me to see a real world scenario

[renyn]

These videos are a gold mine for the guy that cares about his car and would like to work on it himself. Thanks for making them Mr. O.

[zReignYT]

You're a great teacher. I just learned how to properly do a voltage drop test and what to look out for in your videos. And learned a whole lot more. My learning has been excelled from your channel. Amazing work. And amazing craftsmanship. Thank you!

[rgebes]

This is good timing, my college physics 2 class is all about electricity and circuit diagrams this semester. It's cool to learn all the theory but even better to see how it applies. These videos have actually helped quite a bit in class as well as fixing my old f150, which I think is pretty cool. Keep em comin!