I could really use some advise here....I was pulling my camper with the 2017 2500 HD when the Stabilitrac light and the ABS light both came on with the Service Trailer breaks soon on the DIC. I do not get this while the trailer is not connected. I thought it might be the trailer, but when I took some DC voltage readings on the plug- i read -12VDC where on the 2017 Suburban iwas reading the +12VDC on the same Pins..(??). I pulled the break controller out of circuit, but that did not help. And the 12 volt battery pin is also -12VDC ..... what the devil am I missing - or am I just not looking at it correctly and being a dumbass and hve the leads reversed. I have the black lead on the ground (or what I think is ground (7 o'clock position) and the 12VDC hot is at the 1 o'clock position ....this gives -12VDC. would someone be able to help strighten me out here. THANKS

 

do you have the leads reversed in the voltmeter? is this the oem 7 pin connector or has it been replaced by someone?
I would start diagnostics by getting the codes read. you will need a scan tool that can access chassis codes. a cheap code reader can only access powertrain codes.

 

No, meter leads are not reversed. I have already scanned the truck and it shows no code. It also only does it when the trailer is connected so my next step I think is going to go look at the trailer and see what’s going on. I appreciate the answer up though. What I did find was the plug is wired differently than what I have seen before. There is a hot lead on Penn one and a hot lead on pin five. Pin five is for the battery +12 and pin one is +12 for all the other parts brakes lights etc. I don’t think there’s anything wrong with the truck after further troubleshooting.