2004 2500HD 4WD Retrofit Factory Trailer Brakes?

[Deathdog]

You can plug aftermarket trailer brakes into the fusebox. It would seem like retrofitting factory switch could be done? Has anyone done this?

[davester]

I don't believe GM had an factory TBC for '04.  I can't see an option that would appear to include it in the list of RPO codes in the full-service manual for that year, nor is it mentioned in the owners manual.  I believe they just  included a plug with some wires, the plug goes into the junction box behind/below the brake pedal, and you hooked up the wires from that plug to a 3rd party TBC.  And depending on what options your truck came with, you may need install a fuse and/or install various wiring harnesses in the rear to get the brake signal to the rear 7-way plug.

[jhplak325]

GM did not offer factory TBC on the GMT800 trucks, they included a pigtail harness to wire in an aftermarket controller. You also had to install a fuse and hookup wires in the underhood fuse box.