2007 Silverado trailer brake problem [Archive] - Glock Talk


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06-10-2008, 19:49
I have a 2007 old body style silverado, i installed the factory wiring harness adapter for the brake controller along with the 40amp fuse and now I found that i have 12V on the trailer brake wire on the 7 way plug at all times. Ive disconnected the brake controller harness from the relay and the problem is still there. The only way to cure it is to pull the fuse. Something is wrong in my wiring harness on the truck. Does anyone have an idea what is causing this before i take it to the dealership thursday and have to argue with them that i didnt cause this. thanks

06-12-2008, 08:38
Can you take a look and tell me what colors you put with what colors. The 2007 trucks are different, for some reason beyond me, I'll print the bulletin when I get to work and bring it home with me. I can't get to this sight from work, so it'll be later this evening.

06-12-2008, 08:47
Thanks for the help but i figured it out. Who ever owned the truck before me had wired up a brake controller without using a harness adapter and had cut off the wire connector on the blue trailer brake wire at the fuse block, put on a ring terminal and put it on the 12V terminal on the fuse block sending 12V to the trailer at all times. Why he did this is beyond me. I just had to take the wire off the terminal and splice it to the side of the wire going to the brake controller. Guess thats what you get into buying a used truck, never know what some idiot did to it.

06-12-2008, 18:24
Good, glad you got it figured out. I've seen some strange problems when customers wire in their own brake controllers, or other electrical stuff for that matter, no idea why some people do things the way they do. I was a bit confused anyway, the classic is a plug and play and the new body is spliced in. Either way, the 40A fuse is on a circit that goes straight from the fuse block to the trailer connector, bypassing the brake controller anyhow.