Chev 2500HD Factory Trailer Harness Issue

[terryg]

My P3 controller is not getting a signal from my TV brake switch. The switch is working properly, i.e., the TV brake lights work fine, but 12v is not making it to the pin the P3 adapter harness plugs into. I've checked the fuses under the hood and they're good. Any ideas before I have to bypass the vehicle trailer harness and splice directly into the brake switch wiring?

Terry

[ROBERTSUNRUS]

Hi, just trying to help, but how did you check the fuses? GM is well known for installing dummy fuses in places needed for trailers. This has been mostly noted on people who's trailers have disk brakes.

[redeagle313]

What model year is your 2500HD?

Have you ever been to The Diesel Place? It is a GM HD truck owner forum, you can probably find answers very quickly there.

[Foiled Again]

In my 2008 I had to install both a fuse and a wire. Both were under the hood on the driver's side. I don't remember whether the instructions were in the brake controller pamplet or the owner's manual. I'll look but I'm not great saver of paperwork.

Paula

[terryg]

Thanks for all the suggestions. My Chev is a 2004 Duramax. Everything was working last fall when I put the trailer in storage, but somewhere in the circuit continuity was lost during the winter. After checking all the obvious things with no luck I decided to splice directly to the brake switch. Everything is working fine now. Terry