Hi Paul! I’m an EE and I’m not surprised at all that another EE would say that. I worked with several EEs who came out of school and although they knew the academics, they weren’t worth a crap in the field troubleshooting automated industrial equipment. I can remember asking one “How should we test this cable?” This cable was for a 250 amp DC power supply. You guessed it as an ohmmeter was his answer. Then I had to teach him about voltage drop testing which of course he never heard of. 👍

What I learned from u is good continuity does not mean good CONDUCTIVITY Check voltage drop of the circuit current has to flow A continuity test can’t verify the ability to handle the circuit current

Fantastic demonstration of voltage drop testing Paul!

I teach for a major auto manufacturer and we teach voltage drop. We even show where the resistance check will lie to you. It's all about the voltage drop or load testing.

If engineers had to fix the garbage they design today, things would get MUCH easier for us in the shop, that's for damn sure. GREAT explanation as always, Paul. Great to see Caleb absorbing all this knowledge, too. He's probably already a better diagnostic tech than I, and I've been doing this as long as I can remember. 😎

I have proven to myself that the load pro works great for such occasions. Not advertising here but the darn thing works on my meter like a charm. I myself have used the ohm meter and misdiagnosed a simple problem. Spot on !!

I am a retired mechanic of 36 years on the job. I started working on cars in 1980 the first year GM had computers in cars. I did a lot of electrical work and in the early years i was factory trained. I always checked a ground with a ohm meter. You teach me something in almost all of your videos, I wish there were more teachers like you when i was starting. Anyone going into this field of work should at least subscribe to your premium channel i would have went to your classes!!!!! Thank you so much for being you, you are the best teacher anyone could ask for.

Hi SD. I'm also an EE and I was thinking, you can't get the required resolution using a simple ohmmeter to tell a bad ground. As you said, 30A through .1 ohms will show 3V of drop and anyone looking at .1 ohms would probably call it good.. Not to mention, the ohmmeter won't heat up a connection like current flow will. Agreed, voltage drop all the way.

Voltage Drop Testing is always the way to go. Dan Sullivan has been aware of this for many years. This is why he invented the LOADpro diagnostic tool. And this is why I bought one for myself. It's important to mention that you should always make sure that you have a fully charged battery and that all grounds are good and all your terminals and posts have been taken apart and cleaned and reinstalled. The same applies to the Battery Posts the Positive and Ground Cables as well looking for Corrosion and damaged cable insulation. The Voltage drop test will the level of Resistance in the circuit if any. Then you can investigate if the problem is on the Positive side or the ground side or is it simply a defective part that needs to be replaced. I am one of your loyal subscribers. 👍👍

Paul (Not Dan) I am an avionics tech by trade. I have been working on airplanes and cars for nearly 35 years. This includes teaching basic avionics to new technicians at our airline. My automotive education started with a tach and dwell meter, and for diagnostics it was a Sun Interrogator and a Simpson 260 analog meter! What you are saying here (and so many of your videos) is spot on! Many of the fundamentals roll right into the aircraft electronics world as well. I have even had a few of my guys come have a look at this video specifically. I'll be buying your book as I have started to get into working on newer cars as a side business. You are doing awesome work!

Yup SD premium changed my life. Well worth every cent. Highly recommend 👍🏻

That's awesome professor. It's a good feeling proving people wrong. I remember that case study u were talking about the 900 ohm of resistance on that GM vehicle with the aftermarket alarm system that the customer didn't even know was there. Great job professor. Cant wait for the navigator case study. Take care 😀

GM teaches us how to do voltage drop, but really focuses on resistance measurements. I’ll do them on cars where I have no idea what’s going on and need to follow the flow chart (unfortunately) but your methods have really opened up my diagnostic abilities over the last year and I just wish I had more time to go through your stuff

Totally agree. The other down side to Ohm checks is you have to isolate the circuit. Which means disconnecting stuff & ultimately changing the circuit. The Observer Effect at it's finest (the mere observation of a phenomenon inevitably changes that phenomenon). Sometimes simply touching the wires/connectors will 'fix' the problem, sending you down a rabbit hole and possibly never finding the problem. So if you can test the circuit with the circuit untouched, you will have a higher probability of success (and probably develop less gray hairs in the process).

It’s always funny that people comment that you are wrong yet never make thier own content and believe they are right no matter what. This isn’t home wiring this is auto circuits. I bet the guys not even an engineer. Thanks for sharing Paul great job on this.

Using a test lead on your Power probe 4 . Go to Feed mode and touch those same points. The red or green Led will light up / annoying sound to let you know if you have a good ground or power etc...also you can read the resistance at the same time. It will not light up or sound off if there is high resistance. The PP4 will load the circuit internally like your test light. Great learning video 👍 you guys made

Your diagnostic videos are second to none. You are a fantastic teacher.

You teach what works best for you. The do it your selfers will have to make up their own minds. Just keep teaching mate. Knowledge is all we really have to keep. Your work is appreciated.

Thank you Paul Danner for doing what you do .Please keep keeping on brother !!!!!!

Excellent! So thankful a Chrysler training instructor recommended me to your channel! Time to level up my diagnostic skills from a true Pro!

Paul, Caleb, I want to thank you two for providing such great online education, YOU TWO ROCK! (Netherlands Europa) 20:30 EST

I agree with you 100%. Problem is that ohm testing is still being taught to apprentices here in New Zealand, and probably many countries. The use of an incandescent test light is not allowed here in many workshops because of the damage they cause!! Their reasoning is beyond belief. I'm sure some instructors & techs still think the world is flat!

GREAT INFO PAUL! I absolutely love love love the premium channel can't get enough of it you have taught me lots of valuable knowledge even for me being a heavy duty Diesel technician , It doesn't matter I work on literally everything. Appreciate all the hard work you put in these videos 👍🏼

Hi Dan I live in the UK and have been doing diagnostics since the 70s, I did 25yrs for the RAC which is like your AAA but we have dedicated patrols who now have diagnostic readers so prior to that the training centre I ran/managed had nothing but good multimeters for years which give you a good grounding for using a diag tool, and the one thing we had on a sign in the workshop was "volt drop change my life" ,because exactly what you said you can get good resisstance on circuits, coils etc even when they are bad. Keep up the good work Ian

Nice reminder backed up with solid proof! I spent my first years as a tech scratching my head after completing resistance tests and results showed all was well when it wasn't! Loaded circuit voltage drop tests started finding faults quickly and put the joy back in the job!

I first learned about load testing and voltage drops from over on Daniel Sullivan’s channel. Changed my whole outlook on circuit diagnostics. Thanks to you to for a very clear and concise explanation on this and how there major differences.

Glad you taught that electrical engineer something valuable for free that he didn't learn in college. Keep up the great work and proven information doesn't lie. :)

I work at the Fiat Chrysler plant in Windsor Ontario Canada repairing the Dodge Caravan and the Chrysler Pacifica and I never use the ohm meter except to check camera functionality as this is the only way to check if the camera is good or not. I just uses the voltage drop method as it is by far the best way to check things. Thank for this video (and all your videos) as it helps people to understand this.

Haven’t finished watching this, but great point Paul. Basically it‘s like testing resistor in circuit on the PCB board. You can have reading 20ohm of 10kohm resistor. Does it mean that resistor broken? Of course no, it just act as a conductor, therefore until there are current it wont resist anything. Voltage drops and injecting some current are crucial things during troubleshooting electrical/electronic components of the car.

Fantastic vid. I was working on a No Crank No Start on a Bobcat. I was convinced it was somewhere in the ignition wiring. My test light bulb was burned out and I had no spares. At the time, I didn't have a power probe. So I used my multimeter and checked the resistances instead of repairing my tool kit... shame on me. I wasted unneeded time. I eventually pulled my head from my butt and borrowed my friend's test light. I started my tests and checks all over again. I followed the voltage drop test all the way to a hidden damaged wire within a very inconvenient place in the frame that was being held together by a single strand of wire. That single strand was enough to positively test continuity but would drop the voltage.

freaking awesome, voltage drop for the win !!!!! Paul how dare they try to question your skills ??? good thing you showed them !!!!! hey buddy sign up for scannerdanner premium maybe you'll learn a thing or two lol !!!!!Paul for president 2020 !!!!!

I remember this video. Awesome example. I always try to remember we need to evaluate a problem while its happening instead of static measurements. You sir are the man

Absolutely agree. Loaded voltage drop test is the way to prove wire integrity. In the electrical field the utility workers have what they call "the beast". They clamp on at the meter and seriously load the service drop. If there is a weak connection you will see a voltage drop. I might add, even on a short to ground or ground fault i tend to grab my megohm tester. A gfci trouble call can be hard to trace with a wimpy ohmmeter. Put 500 volts and ground fault shows up easy. (Not for cars) love engineers but sometimes......a little experience goes a long way! Cheers

A bad ground is like a kinked garden hose, an ohm meter is still going to show 0 ohms and voltage on a bad ground. Put a load on the bad ground and you will see the like kinked water hose, when the voltage is not there like the supplied voltage. nice video Mr Danner.

Best driveability teacher. Makes sense always

you guys are the best. now on with the show ❤️️ much easier to do a voltage drop test or computer ground test and leave the ohmmeter locked up. Thanks, Paul and Caleb

I agree. I believe you should know ohm testing on a fundamental level but should master the voltage drop testing. The times I’ve mostly used ohm testing is if I think I have an intermittent break in the wiring and I would use the graphing meter on each end of the wires and start wiggling the harness.

The EE's flow charts don't Stress, Load, or Strain the wires in question as you have by turning the key ON, and pressurizing the circuits to their normal capacity, to "catch" excessive drops in voltage with Ground- to-Ground voltage drop checks. I've heard it called 'stealing" voltage from the circuit, which in your case was the corrosion . I hope this makes your case stronger!!

I totally remember that Toyota video..Lol. Great lesson on why voltage drop is best. Thanks for sharing this Paul. Great video.! Put that freaking Ohmmeter BACK in the toolbox.! 😂😂👍🍻 Cheers Brotha

Really appreciate ur vids man , honestly I’ve learnt so much for ur content it’s made me a much much better tech

Watching every single video of yours. Wish i could have seen all your videos when you started your career. Absolutely awesome videos. Calib you are blessed to be part of your dads business. First hand info. Absolutely brilliant. Thank you very much. I am not a mechanic but do work on peoples cars. Absolutely brilliant. Luv everything. Cannot get enough of your info. You are helping so many people. Watching your video, then go to my toyota to do same tests where possible. 👏👏👏👏

I’m curious if this EE went on to explain how he would prove a bad ground with just his ohmmeter???

ScannerDanner. I thank you. Your theory on chequing the voltage drop. Am not an electrician. I don't know why people who are experienced electricians. Can see the easy practicality of your sureshot tecnique. But it sure will make second guessing. Away with the useless time wasted. You're right on the money. Ohms quantity testing - Like you said on the engine grounds going to the computer. It's a waste. Unless you take your time to inspect the conditions for a solid ground. Going to the computer 💪💪. Always checking voltage drops. I would say. On every electrical problem is 🔑👍. Making sure the relay is okay every time.

Garbage in Garbage out!.. load test/voltage drop test all power supplies. Fantastic video. The engineers are the ones that make these awful misleading flow charts.

Only can use ohm meter on airbag systems. Older hondas ignition coils show perfect ohms but a no start. Replace coil starts right up

Scanner danner is the man! 5 years out of trade school and still learning much more than shop foreman with 15 years in one make can show. Premium is on your website correct?

You are one of the best, and you are very humble and down to earth.

Great video Paul. As an automotive lecturer in colleges myself I regularly inherit learners/mechanics/apprentices with a sort of beginning knowledge of electrics in need of improving. This exact point - that the pittance of current pushed by a multimeter battery doesn't load the circuit, and therefore a terrible ground for example would 'pass' an ohmmeter test - is one we have to regularly cover. REPEATEDLY. :) The solutions are several - repeated examples (also I direct them to your book and vids as you know :) ); a revisited firmer command of the basics; simply getting them into the habit of saying "volt drop" not resistance sometimes helps a little too. The problem is that to a basic understanding their mistake (though still wrong) is based on 'correct' statements. So that bad ground for example. They have the following basics: "the problem could be too much resistance" "Resistance is measured in ohms" "An multimeter can measure ohms" and from those 'true' statements they draw the wrong conclusion "therefore a multimeter set on ohms can test this bad ground". To say to them "yes, in a sense the problem IS too much resistance...and I DO get WHY you would think that...but you can't test it by directly testing resistance per se like that." makes their brains hurt at first :) So as much as I (and eventually THEY too) understand why this is wrong...I do have some sympathy as I get WHY they make this basic error. BUT....That 'experienced mechanics/technicians get this wrong though...there's no excuse. And as for the 'electrical engineer' that had a go at you. ha. :)

Hi SD. Think it could be my comment you refer to in this vid, i`m so pleased and impressed that you made this one to clear up the guidance of the previous. Yes of course we can use a scope, which i would suggest is maybe a piece of equipment that a lot of people don`t have available to observe diff characteristics but in that demonstration you were utilising a lamp which for me is vague indicator. What i was aiming to suggest is that a loop resistance test is far better than the brightness of a lamp as a means of analysis and yes i could have suggested a voltage drop test of some sort. Thank you, i remain a big supporter of your information and guides and was merely attempting to add guidance as opposed to criticise. I meant well.

It is simple that an ohm meter doesn't provide enough load to a circuit to show a high resistance, a loaded test will show a fault where an ohm meter won't. Great work, Paul.

Agree with the voltage drop test! ScannerDanner Premium is money well spent as I have been a subscriber since the beginning and have been educated on many test procedures.

Engineers is the reason why techs exist. Techs repair what engineers got wrong.

awesome video, I preach this whenever I diagnose the issues that the other techs in my company fail to figure out and have reached the end of THEIR rope, ohm meter readings will say yea its good at this low current level but the real situation is revealed when you put the pedal to the metal and look at what's going on while real operating conditions are in play.

Dan Sullivan the guy who invented the load pro test leads, would always say in his videos that the problem is usually something simple. Case in point you found a corroded grounding spot on the engine block. The diagnosis may take some time, but the solution is something so simple.

i have never trusted ohm tests on circuits like this one, i have been caught out by this in the early years, another great vid mr danner.

I got "burned" a little using the DVM a few months ago fixing my horn circuit problem on the 1999 Silverado; the test light came to the rescue and proved I was chasing a ghost..

I was testing a GM air conditioner system on an S10. I had power everywhere it was supposed to be, had ground too. Circuit still failed to operate when i plugged everything back in. I switched to a test light and checked my meter, power, when i touched test light it dropped to "0". All became clear, LOAD THE CIRCUIT!! It was a bad relay, burned contacts the post mortem revealed. So i am absolutely on board. I have also discovered that electrical engineers generally go by the mantra "looks good on paper", as we know, in reality outside the draft board, its all very different.

👍glad there's teachers like you keeping things real world. Hope to be part of the premium channel some day. Just too busy now. Thanks!

The health of a circuit can only be determined when it's capable of flowing the designed current at the designed voltage. Makes total sense really. No one builds a circuit for the end-result of a resistance specification. The whole purpose of a circuit is to carry a specified current at a specified voltage.

Sir Paul thanks for your kind teachings may GOD BLESS YOU AND YOUR FAMILY AMEN

Many good points here and I'll make a point too. Comparing a low cost/accuracy multimeter to a high cost/accuracy scanner/oscilloscope isn't fair. And I'm with you on volt drop testing too.

Since this is the latest video, I hope Mr. Danner gets to see this question which is perhaps more of an opinion. Furthermore, I hope he forgives the long post. My second profession before I retired had been working as an electrical contractor. Mainly in residential and office building market. The electrical system in a residential unit consists of three wires that come to the top of the house electrical panel and a GROUND wire that usually comes out of the bottom of the panel. This heavy wire connects to the house cold water pipes that are buried in the street (ground) and usually an eight (8) foot solid copper rod that is driven into ground. Called ground rod. Basically, the purpose of the ground system is to protect an occupant should a live wire touches the body of an appliance. The ground wire in an outlet or appliance, routes the live voltage to “ground” rather than the body of an occupant. Thus, preventing a heart attack. Now the reason for this post---I know I am probably going against many years of automotive electrical charts and training books, so bear with me. Why a body of an automobile is called “ground”? There is no connection between the vehicles body and the earth. Rubber tires prevent an electrical connection. In a simplified DC circuit; in order for any circuit to work, it requires a path for 12V positive to reach the load. It also needs a path of return to 12V negative, which are the two terminals on the battery. The automotive engineers figured that since there is metal in the frame and body of the powertrain, it would save wire (money) to use the frame as the path for negative voltage to battery. That is a great idea, but why call it “ground”? Why not call it chassis? After all the negative wire of the battery is connected to the chassis of an automobile. Anything, but “ground” makes more sense in a DC system.

Great info dude! You’re right about flow charts using an ohm meter for testing, but when I go to Honda training (I’m an Acura dealer tech), they really push voltage drop testing now. So factory training is doing the right thing at least. I view flow charts as more of a guide 😆

Another excellent video...Thanks!!! It's like one of those movies you need to watch multiple times... Working with circuit boards, so often I see where the power looks just like that jittery wave of your ground in the video (almost always a cold solder joint)...I'd say 75% of most circuit board failure issues are power-related (and often mechanical in nature)... Forget about it...considering the load of a measuring device?....Make everyone cry. Thanks again.

Great video Paul and nicely explained. Voltage drop testing all the way!

From Nick Ayivor from London England UK 🇬🇧 ⏰ 23.47pm 21,04,2022 Thank you very much 👍 SUBSTANTIAL Sir ScannerDanner

Good on you Paul, this is what I learned in school. Volt meter and incandescent test light are your friend

great point SD PROVING OUT THE CICURIT WITH CURRENT FLOWING all the best

Good job good teacher l always enjoy to listen and learn from you and thanks

Great informative video, good to see you revisited the important test procedure.

Would like to know your take on the Sullivan Load Pro leads for meters...

Current handling wire and connections with dissimilar metals & corrosion will get you over time; happens all the time with aging "stuff"; more so in the "salt belt" areas of the country.

Great job Paul. I’ve tried to convince my coworkers that voltage drop testing is more reliable but it falls on deaf ears. Mike

0:51 not to make fun of the engineer or all engineers in general, i(FNG as a dealer tech) had a 15 sienna come in for a no-a/c complaint, found out it has a code for the clutch lock-up circuit(essentially something that sends the signal to the computer to request a/c operation) well this vehicle had a new clutch-coil put on at the previous toyota dealer(out of state, why they put a clutch-coil on i dont know but thats what they did) but its still not working, fixed the pin fitment issue that it had in the circuit but it still didnt work, so now i(the FNG) took out my ohm meter and said well the coil has 200ohms(it was right in the middle of spec) of resistance so it must be good, take a closer look and you will notice the wires were not routed correctly so now did i just measure the resistance of my pulley? new clutch coil and it works now, ENGINEERS! WE LIVE IN THE REAL WORLD! resistence measurement is not always the way to go, i personally try to use a test light(kinda like what SMA made in a video) but ill use the peanut bulb for circuit integrity to check my wires, im sure i will get a lot of hate for this comment edit: curious how bright/dim the test light would have been in that computer ground before the fix, thanks again for the great content!!

You’re a badass man!! I hear a lot of people saying you’ve changed their life in diagnostics. I wanna better myself in diagnostics. So guess whos joining your class? 🙋‍♂️🙋‍♂️

I've seen voltage drops in battery cranking and charging grounds. One shop couldn't understand why they were changing batteries (2) in a large truck. Battery ground was at a steel plate less than 1 foot from the battery. The steel was part of a steel body bolted to the truck frame, and there was a large flex ground jumper from the frame to the engine. One new triple ought (000) cable from the battery Negative to the engine block and a 2.6 Volt voltage drop went to .7 drop during cranking. No more battery, cranking and charging problems!

I've seen the original video many times. Very good information related to testing grounds.

Awesome example of what you could be missing, this is the kind of stuff with an ohm meter that would cause head scratching and possibly replacement of an part that was good.

Good video danner. I got burned on a lin bus recently... ya low current circuit that the ohm meter said was okay. Gotta load the circuit...

I use an ohm meter quite often for things such as verifying I have the wire I want or that a bulb is good but for checking the integrity of a circuit I’ve used voltage drop tests for years in both automotive and aviation. An ohm meter just doesn’t produce enough current to identify a less then perfect ground or wire integrity.

Can't wait for your next live! Loved to see NLA in the comments and getting ready for a camera man!

Learned this long ago. A test light doesn’t lie! If I followed every flow chart I would have replaced a ton of modules that weren’t bad.

Great video! I never had to follow what a manufacturer was telling me because I've learned the correct testing procedure from Paul Danner and other great diagnostic KZfaq channels! 👍

I use voltage drop testing a lot of the time to pin point or get a general idea of where the break in the wire is or where the corrosion is. I really like to load test, I built a small load bank that can draw about 11 amps at 12.6VDC, you can draw in .5 amp increments on 4 switches and 1 amp increments on 4 more switches. It displays voltage on the circuit and the amount of current you are drawing. I see ohm meters get guys in trouble all the time. Manufacture troubleshooting sucks most of the time. It will lead you down a rabbit hole if you are not careful, and you will not recover your labor from them instructing you to basically misdiagnose it. I have spoke to a couple of the manufactures that my shop deals with and they more or less scoff at me when I bring up the use of oscilloscopes or dynamic circuit testing. "You can't do that you are going to damage our product!" Maybe, if you don't know what you are doing. I have never cooked a board, but I have diagnosed and repaired a lot of things that troubleshooting trees have missed. Love your videos man, you putting out good information makes us all better techs.

SD is the GOAT

I'm also an engineer and I say use an ohm meter Danner cause does what my tech manual says!!!ohh and I confirmed that with my poodle and she suggested the same thing.

Paul I attribute this to the fact that many do not understand the fundamental relationships contained within the confines Ohms' Law. And if we do not understand the solid ground of those relationships then our understanding of Kirchhoff's' Laws are built on sinking sand.

if it's a bundled ground and the car isn't running the load may not be right and voltage drop could be wrong. always make sure the circuit is loaded properly or heavily! yeah, repeating what you said more or less, people always forget that ;)

Another great video ohm meters and resistant testing has its place and you are right high current wires need voltage drop testing will I don’t use your test lite method I do amp testing of the Circuit and yes only with the modules disconnected and after studying the diagram I check to see if the circuit can handle at least 10amps today’s vehicles uses more modules to control everything and electrical engineers really do not deal with corrosion , chafed wires and bad repairs to the wiring like we do Ps I have seen a signal like the one in these video but it was not a bad ground it was a bad alternator diodes pushing a/c in to the electrical system it’s funny what havoc a/c voltage plays on this systems lol

Great video Scanner Danner. Voltage drops test is the only way to go.thanks for all your amazing videos your a very sharp tech an trainer. I call my test light a scope on a rope.

It can be the manufacturer give me advise but you still number one teacher in my book of automotive Scanner Danner aka Paul the man

Yeah, that is a good video . I watched it a long time ago . Voltage drop is the best way to test circuits

Electrical engineer just got burned...good content Paul

Paul, great video!!!!!!!!!!!!! Flow charts are like chasing ghost's down rabbit hole's!!!!!

Diag tech for Audi here and they teach and only recommend voltage never ohm meter

fact I went to Nashville auto diesel 2001 15k I learned the material now I a danner premium guy fixing a lot from his teaching. like a car or truck comes in late I kind of know what direction to go the next day so I watch mr danner premium channel at night bam the car is usually fixed with what I learned in less than a hr billed out the door if you own a car or truck worth the 11.00 to know how it works trust me it is going to break down DO YOU KNOW WHY. DANNER MAY BE ABLE TO TEACH YOU. thks paul

I just had a great idea coming from the HVAC business 90% of technicians do not know how to use a multi meter or ampclamp Why don’t you try doing some videos on HVAC equipment troubleshooting I bet you get one hell of a response good luck

What do you do on a car that randomly stalls? Dealer had had it for 2 weeks, no stall. I will take it home and 2 or 3 days later it will stall. Usually happens on a very hot day with a/c on. Never has a fault code.

Yes you did it with your experience 🤍

hi how are you , i have a car that have a high camshaft sensor voltage , can you make a vedio about it? i cant find the problem