What's the chance someone could have jumped my Yukon reverse polarity causing damage?

[KR66]

My 01 Yukon was running great until after I left it at my sister's house while moving, I had a Camper I needed to tow with my truck before I could retrieve the Yukon. I just remembered they said the battery died in it and they jumped it to move it. I know my sister didn't but my brother in law who I don't think is very bright because he almost burned her house down . If he connected the jumper cables backwards could it have caused the Fog lights, Cruise Control and Door ajar to stop working? I've been looking for chewed wires , broken ground straps, blown fuses and bad relays , everything seem fine. The Fog light relay has power and works. When I check the voltage at the fog light bulbs one gives me a low voltage 9-10v the other nothing? The battery is at 13.5v. Could the ECM have been damaged? My code reader doesn't seem anything different than normal. I'm completely lost at this point what to look at the Yukon is/was in perfect condition for its age until I left it in the care of someone else. I don't have any proof he reversed the Cables he's not the kind of person to admit fault any help how to figure this out. It's really ruined it's sale value.

 

[Big Mama]

Gotta love brother in laws. Since it was parked have you checked the bulbs? I believe there’s a ground on the base of the B pillar on the bottom. They go under the sill plate and can get pretty crusty. As for your question I’ll defer to others but I think the relay to the BCM or ECM would blow before power got there but that’s just a guess.

 

[KR66]

Gotta love brother in laws. Since it was parked have you checked the bulbs? I believe there’s a ground on the base of the B pillar on the bottom. They go under the sill plate and can get pretty crusty. As for your question I’ll defer to others but I think the relay to the BCM or ECM would blow before power got there but that’s just a guess.

The bulbs are definitely ok I pulled and checked the with power directly from the battery. I know the relays are working I checked them all.? The odd thing is One Fog connection gets full voltage but I guess not enough amperage to light the bulb the other is getting 0 volts? Oh and I also lost the Door Ajar warnings for all doors on top of the Fogs and Cruise Control. I just replaced the IAC because It started to stumble and stall at Idle but now it's Idle is erratic? Something definitely happened I just can't find it.

 

[nonickatall]

I had the same problem, my Escalade was empty after sitting for a long time. and I was hectic and thinking and tried to bridge my vehicle and swapped the poles.

It made a violent flash, I removed the cable immediately, but then I had the problem that the car started, but the central locking no longer worked, the instrument cluster no longer showed anything, the radio was dead and so on.

I was totally shocked and thought I had sent my beloved car to the great beyond.

I then found out that a fuse in the front of the fuse box, one of the big square ones at the top, had blown. After I replaced it, everything was fine.

Here is the tread:

Ruined my electric system, need help

Hello folks, I was on vacation for four weeks and wanted to start my truck up again today. The battery was dead, I took another battery and a jumper cable and wanted to start the truck. I connected the cable and stupidly didn't look properly, because I was in a rush and connected the battery...

www.tahoeyukonforum.com

 

[Doubeleive]

ya if you screw it up with the battery the fusible link or megafuse or others will do there job. I was installing a amp in my truck and it shorted directly to the battery (new out of the box amp) let a bunch of smoke out. after that about half the electronics didn't work, turned out it blew one of the fusible link and about $120 later I was back in business like nothing happened other than the $650 amp was now garbage