Factory Tow Package on 2006 GMC Sierra Not Getting Power To Brake Controller

Question:

Have fuses in main fuse box under hood for trailer controller. Plug the controller wire into junction box under emergency brake level correctly. Do not have power. When checking at junction box do not have 12 volt power. I do get brake pedal signal when brake is applied. Do have ground connection at terminal. Does GMC not wire the power wire to the second slot on the terminal wire. One of the other wires connected on this slot which you do not wire to 2 on the rigtt and down has 5 volts registered on the volt meter.

asked by: Bill

Expert Reply:

It is possible that the power wire that feeds the brake controller has not been connected at the power distribution box under the hood. If you look at the brake controller installation help article I've linked to, you can see how the wiring connections are finalized. This usually applies to vehicles that are NOT equipped with the factory 7-way trailer connector at the rear bumper. We have seen vehicles equipped with the 7-way that don't have the connections made, so it's worth checking.

If the fuse is good, and the wire shown in the provided photo is connected, there's probably a break in the wire between the post and the brake controller. If I were in your situation, I'd just run another battery feed for the brake controller. On your 3015-P wiring adapter, cut the black wire, and graft on a length of 10 gauge wire and run it to the positive battery terminal via a 30 amp circuit breaker like part # 38630.

expert reply by: Mike L