I made the WRONG CALL? (Wiring Variables - How to Test INTEGRITY) 

There's making the wrong call, and then there is dealing with hack jobs that change parameters that lead people astray.

As usual. I learned something. That's why I watch this channel. I always get little nuggets. I usually load check circuits. But not in the practice of doing it when doing simpler tests. This video is great example that load testing should always be used.

I prefer using an ohm meter to check for shorts, since it will also find high-resistance "shorts" that are low enough to corrupt the data line but not low enough to light the test light. I also like to measure between the different wires, not just between one wire and the body.

Thanks GM for changing the pin layout in a harness in the middle of a model year for no apparent reason.

Test light for the win.

Eric would be proud that you mentioned the scope on a rope.

In the UK we have a phenomenon called Sod's Law (do you have that?). It's like Murphy's Law only worse. In your case, the Denali problem was more of a case of SODS Law coming into play where the information on the VIN was incorrect and sent the shop down the wrong road. If you can't rely on the manufacturer who can you rely on?

Everyday new things,I like the loaded circuit integrate test. That was sweet. Thanks Evan....

Great job on both vehicles! I can see how the second car would lead you in the wrong direction with the meter. Test light is the way to go. I love your little test light setup you built 👍🏻

Thanks to you, in an earlier video you had almost the same issue using an ohm meter, and when I had a circuit in my RV go bad, I remembered what you said. Saved me a LOT of grief when I put a test light and found a grounded circuit (and I was even able to locate the issue)

2 in 1 video, yay!! Nice teaching Ivan, thank you!!

Nice video! As a lead body tec I get to deal with those issues from time to time. Btw thanks for teaching us I always find something useful in your videos.

ford had something called BLIS blind spot warning which was a bad system where the radar antennas in the rear bumper were often destroyed by water and anything else that hit them. they had an incredibly thin plastic housing

The Denali wiring is crazy! What a boobytrap!! And the Equinox was crazy too, just not as tricky. Good going! You showed them who's boss!

Parts man at dealership ordered wrong harness. X88= Chevrolet, Z88= GMC, Z75= Cadillac. Working in parts department at GM dealership those are practically the first 3 RPO codes an individual would learn as any C/K truck built has one of the three codes in the spid label. Lots of part numbers provided in a body shop estimating guide are just that, a guide to aid in the creation of an estimate, and should always be checked against the GM parts catalog to ensure the correct part, especially wiring harnesses, trim and moldings.

I think that you would see some form of grounding with the ohm meter as well but yes current carrying ability is always a good check.

There's actually three wire tests you can run - continuity (multimeter), load (test light), and impedance (signal generator / network analyzer). Just because a wire passes continuity checks doesn't mean it will carry a load. But just because a wire will carry a load doesn't mean it will carry a signal. A damaged wire or the wrong kind of wire may have a high impedance at frequencies other than 0 (DC aka the test light). Think a CAN wire.

11:09 Sandals Baaahahahah Ivan's safety boots

Thank you for the update

I would have bet that the owner had ran that truck through a car wash and forced water into the side object detection sensors and that set so many codes that it forced the medium-speed CANBUS to shut down the vehicle and to repair it would have cost $5,600.00. I am glad you were able to help, Ivan. Bonus footage that is over half of the video? GREAT VIDEO!

IVAN, AWESOME/ GREAT/ INFORMATION ALWAYS LEARNING FROM THE BEST REALLY APPRECIATED ALL THE INFORMATION IN THIS CHANNEL THANKS FOR SHARING YOU ROCK BROTHER.

Thanks Ivan!

Great one Ivan. Thank you!

That wiring change on the Denali/Yukon was a trap waiting to happen. I like how you re-pinned the module to prove your theory. Kudos for solving the puzzle caused by GM engineers and the body shop. The wiring analysis on the Equinox was very cool as well. Unfortunately too many techs out there still use the ohmmeter method without accounting for the load. Thanks for the lessons.

you are definitely correct on wire integrity and using an ohm meter. You need to run some current through the wire(s) higher than what the ohm meter develops. Good video!!

You can still test it with an ohm meter to ground and it would have also found the short. But I still agree, corrosion can have a short that changes when you add current-- always current load the circuit: test light for the Win.

Great explanation sir.thanks 👌 cheers

Youch! I see this a couple times a month. Watch your RPO codes when programming, too. The RPOs listed by SPS2 for the two variants WILL NOT appear in the door tag scan and have to be pulled by VIN to get the full build sheet. It is also VERY common to find the wrong part in the right bag. We've come to call these "Covid Cars." During the pandemic, especially within GM and Ford, there were a lot of last-minute adjustments made on the assembly line to utilize parts on hand, including alternate wiring harnesses, ghost modules, phantom coding, and all sorts of other fun little anomolies. These are all tracked internally by GM, but on GM and Ford vehicles 19-23, sometimes even scanning the QR code or ordering parts by VIN won't get the right data. Always request a full build sheet from the GM parts counter to get the actual configuration of the car, and run the VIN for TSBs to determine if there are ghost modules or features coded out that require special service procedures. :) As for the Equinox, roof skin jobs are always fun diags. Pinchy pinchy! :D

you can also check continuity to ground for each cable using a multimeter.

With the Yukon,I would just repin the wiring harness & leave it be, with the Equinox I would test for continuity of the wiring harness as well as a short circuit to ground using the Ohms setting on my multimeter as an electrician. They are actually talking about placing me in an electrical engineering role in my trade now !

Yes Ivan wire integrity I like applying a load when checking. Good continuity doesn’t mean good conductivity in this case the ohm meter would have done it’s job but that leads to 3 other wires not knowing if they can handle current your way loading the wires is spot on CHEERS

I had a similar issue recently with a harness that metered OK but had a short between two wires. Just for a bonus it also had a dodgy plug probably from being plugged in and out too often. Moral of the story is just because you find one problem doesn't mean you've found all the problems.

Nicely done!

That's cool doesn't have to be a long one I like these when you doing more couple of weeks at least used to do one a day which is really cool

Ivan, can you please show and explain how you made your test lights? Bulbs, wire and when and where to use them.

Also good point using two test lights. I would normaly use a jumper and one test light. the two test light setup is superior

That's pretty cool so you did two videos and one I like that

😂 for a minute I thought you were going to say " load pro ".......

Never thought of doing it quite like that, quick and easy. I have always done end to end ohm reading then short to ground and power tests with a single test light then if all else fails load test on circuit. been burned on a data line where all tested good but circuit couldn't even twinkle a headlamp bulb. Nice work boots LOL

The trucks inDenali 😂

I like those genuine Yankee work boots you are wearing.

Awesome Ivan! This video just proves can’t OHM everything lol

I likee how you thinkee

Hey,Ivàn I've never trusted a Multimeter for An integrity Check. Wire integrity fix. No pàrts required!

A thorough check could have been done with the ohmmeter if the wires were tested for a short to ground and also for shorts to each other. Current carrying capability needs the light for sure. Long live the DVM! 😉

Hey Ivan you could have pulled out the LOADPRO for that integrity check 😏

I use a 12v buzzer/bulb combo so I don't have to keep watching the light when I go searching for pinched wires.

You can also use a Megger to test for Insulation Resistance that would find the short-to-ground, short-to-shield (if shielded), or short-to-(other) conductor.

where in the headliner was the short do you have that info like around the door middle on lights where ? helpful to make sure others are careful on theircars if adding even a factory option or even replacing the liner like at ray Rainman repairs hey had to redo his liner because of it was in bad shape so he ordered a new one to put in plus new carpet too

the wiring diagrams are for UKC+Z88(rpo code for GMC)/X88(rpo code for Chevrolet). the other choice is UKC+Z75 (rpo code for Cadillac). so most likely what happened is the person ordering parts did not have the vin filtering turned on . many times aftermarket shops make their own pick list and do not order the right parts or they order the parts they think should be the same, because of availability. or the aftermarket shop thinks they know better than the gm dealership. my .02

Hi I wonder if you can advise me. I own a 1997 Toyota Landcruiser Colorado here in the UK, could you tell me if it is possible to have a new key fob made . I have owned this LC for 15 years and intend to keep it, it is in first class condition and runs great. I have tried the Toyota dealer in Wolverhampton and they supplied a master key (un programmed) which I don't need. I don't need any keys cut just the fob. I hope an aftermarket fob is available but so far no luck. I have watched quite a few of your videos and I am very impressed with you and your diagnostic skills. Regards from the UK Paul Reynolds.

I alway save the old parts for a few weeks. Just in case the new parts fail, use as backup.

Why use the small bulb and the test light together and not just the test light alone? The test light alone will allow too much current? Great video, thank you.

You can find that fault with a digital ohmeter, but you have to know which tests to make. Test every wire to every other wire for high resistance, and test every wire to chassis and battery positive for high resistance.

Hey Ivan, I liked your steel toed safety sandals, Are they OSHA approved?

Yes, it is quite the 'thing'. Body shops have found that they can make more money by replacing the entire roof instead of fixing a damaged roof. Some roofs must be replaced because of severe damage. However, shops are cutting roofs off due to hail damage that can be fixed with paintless dent repair and other proven methods. Shop managers make a cut in the cost of parts and roofs can be very expensive.

Always measure continuity to ground with an ohmmeter when checking wire integrity!

Yes, very nice to use test light. I understand what the point of the test light is. Let's say you are going to test positive and negative volt wire but you take the test light on a data line wire and run 12v into it. What happens then?

For wire integrity, wouldn't you also need to check for shorts between wires and each wire to ground? Okay, you did find a ground short but I always use an ohm meter to check for ground shorts as well. Don't need a test light if you do this but for current carrying capability, a test light is useful. I had a really hard time with thd rear AC blower on my 2004 Suburban. Harness checked out for continuity but when there was a substantial current draw, there was a no-connect situation. Connector behind driver side foorwell cover had a burnt contact (diagonally opposite corner of truck from rear AC).

On the pinched wire job, you have to evaluate yourself when doing body work on every vehicle made after around 1995 or later due to the various wires, modules and so forth. Just to be on the safe side, all the body man had to do was maybe spend another 5 minutes being super careful when working the roof panel replacement or by having a helper when needed to be super careful when aligning up the new or removing the old panel. Who knows, the grey wire could have been pinched from when the roof panel got damaged and it went unnoticed by the tech. NOW, look at the time consumed to locate and correct the culprit...that is when you decide more time and concern needs to be taken when doing a job you probably are comfortable with from past experiences yet being more observant will pay off in the long run.

Some of those trucks that were built during COVID don't actually have the BSM modules installed. There is a tsb about that. That's not the only system with the same kinda issues😊

On the Yukon why couldn’t you swap the correct wires in the connector and make it work. They plugged in correctly and just needed the wires shifted to correct sockets in the connector.

Ivan, do you have a recommendation for a basic wiring connector kit? I’m always struggling with finding the right fitting, and end up using pins or paper clips or some such. Thanks! - Kip at Promasters Only.

If you used an ohm meter and checked those wires for continuity and to ground you would have found it also.

Common for those rear bumper harness's to be wrong. Common spot for that harness to get pinched is the visor screws when they reinstall the headliner.

Wondering why they would change the pinout, maybe it was out of their control or they added features and did not want them to be interchanged accidentally.

Since your wrong call was made due to the fact the replacement wiring wasn't correct, how do you handle the diagnosis guarantee? Is is all on you, all on the shop who put in the wrong harness, or do you split between the two?

😂 2/3s ot the video is bonus footage

Ivan, can I assume the shop just replaced the GMC module with the one you re-pinned, or did they replace the harness?

Ohm meter would work if you checked for grounds also ,

Ive got that same two channel scope and yet to have used it!

A continunity test tests for an open. Testing between each individual wire tests for shorts. Using a good body ground then probing each wire tests for grounds. And it can be done with a digital VOM. There are only three posibilities when it comes to wiring. It's open, it's shorted, or it's grounded. The real stinker is finding a high open. A wire that is broken in two but under the right conditiins still works. The insulation looks great, but the wire is broken under the insulation. And unless the insulation looks funny at the point of the break, a tone or a test set used to find opens needs to be used. From experience, the insulation doesn't always look funny above the place where the wire is broken.

On Kia's we have to replace both modules even if only one gets damaged

Would Dan Sullivan’s loading test leads work and a test like that and if so, and if you have them could you demonstrate.

👍

I saw a Ford F150 with leaking tail lamp housings that are not serviceable yet they have the side impact modules inside them. Corrosion took over and the only solution was to replace both tail lamps and harnesses because not only did they operate/communicate with the side modules but a handful of unrelated communication with other electronics. So, two tail lamps, two harnesses and a few other items and $5,600 later in parts expenses, the side modules were fixed as were other codes that showed up because of the tail lamp housings. HOW DUMB. In this case, I have to suggest that the VIN and the RPO codes are needed to obtain the correct parts so I place some blame here on the parts department for not asking more details about the correct part for the RPO list on the vehicle. Also, the shop owes this customer a NEW factory harness, not a splice job, which could be part of the problem and especially where the splices are, behind the rear tire and subject to the worst conditions any splice could be subjected to !

Side object detection system…. Idk about that. Most people just call them mirrors….

Even after the vehicle is fixed you should keep the parts for up to 3 weeks

Equinox works only 2 days a year .. once in spring and fall 😊

Two types of systems in one vehicle. Leave it up to GM for that. But what happens if it's like that on other vehicles? How many other makes have RPO code labels in the vehicle? Unless you have GM repair software that point's that out, you don't know for sure. That's a new one....roof replacement. I've seen pinched harnesses after the body shop installed aftermarket bulkheads that separated the driver/passenger area from the rear of the van. Good videos Ivan!

Where do you get your diagnostics

What do you think about load pro ?

Hi everyone this discussion is hard for me to comprehend. Is there a good book out there to teach me about this load test, ohm, continuity? I'm sure you guys started somewhere to learn all these. Anyone here willing to help me? This discussion really fascinate me and want to learn it too if any soul out there can help me where to start. Thanks!

Here’s a nice fun fact I learned, the new gm’s (at least Chevy) don’t have the rpo codes anymore in the vehicle. I had to request the rpo/build sheet for my 2021 Silverado and printed it out and stuffed one in the glove box and one in my paperwork Edit: I guess it’s now a QR code on a certification label, hope you have cell service when you need parts lol

serious question what is your hourly rate for diagnosing problems... just a rough number...

Moral of the story= Don't pinch the paycheck of your employee or he will pinch your harness and pull the other one down on to the hot muffler one of life's best lessons 👹

Does anyone know what multimeter Ivan uses? GM wants me to buy a Fluke 87 but they are so expensive.

Are those lights homemade or where can you find them?

I'm glad you clarified using ohm meter to ground because that most certainly would have found the problem without the foolish bulbs in this case and would have been quicker !

What am I missing? How did it work AFTER they replaced the wrong harness for a few weeks?

I use my eyes to detect anything on either side of my vehicle. The whole thing is getting preposterous.

Don't feel bad Ivan, we all make mistakes. I made one once, back when I was a lad. I thought I was wrong.

You are supposed to replace your roof every 3 months or 3k miles!

There's no reason you can't find a short to ground or a short between wires using an ohmmeter. You only did one of several checks that are possible with an ohmmeter.

Rigging up all those test lights simply to check for a short to ground is completely unnecessary. You can easily do the same check with your multimeter while you are testing wire continuity. BONUS COMMENT: You should also check for shorts between the individual wires during an integrity check.

Great job, as always, Ivan! This is the last time I comment or like your videos - YT has blocked me from watching, because I have an ad-blocker. So, until ad-blockers can respond to this, I can only watch in Private sessions, which prevent me from liking or commenting. No matter how much I like to be here, I will not be infested by stupid ads to do so. Sorry!

I make it a habit to hold on to every old part I have to replace for up to 2 weeks after the car is finished. Mainly to satisfy the customers and insurance adjusters to show that the parts in question were replaced. And can show why. Because sometimes not even photo and video proof are not enough. But hey, great tip for checking wire integrity. I've been fooled a couple of times testing with just an ohms meter and everything checks out. Then check again later with a test light and the problem finally shows up.

Electronics in the bumper. That’s the real problem. No need for all that.

You could have detected the Equinox signal wire ground short with an ohm meter, but you didn't test for signal wire ground shorts. So your contention to leave the ohm meter alone was wrong. The proper instruction would be to test for ground shorts.

wayback.... 1/2 century ago..... the continuity meters that were NOT HIGH IMPEDANCE were preferred for continuity bcause they loaded the circuit thus eliminated the 'single thread' types. Test lights of proper current are perfect for this purpose.