How to Get 12 Volt Power to a 7-Way Trailer Connector on a 2008 GMC Sierra 3500

Question:

how do i make my hot wire to trailor connector hot. the book said to let qualified person do this, no instructions. 2008 GMC 3500 Thanks

asked by: Ricky

Expert Reply:

Your 2008 GMC Sierra 3500 should already have the wires run for a 7-Way, even if there is not a connector at the rear of the vehicle. If you need a 7-Way connector, use Twist-in, 7-Pole, RV-Style Trailer Connector for Chevy and GMC Vehicles - Vehicle End, # PK11916. I have included a video below that shows the location and installation of this plug.

To get your trailer connector completely wired, you will need to start under the hood. You can also make the connections for a brake controller, should you ever decide to use one, at the same time as the 12 volt lead.

First, remove the cover on the power distribution box on the drivers side of the truck. The terminal for brake controller power is directly to the right of the power distribution box, taped to a wire harness between the drivers side front fender and the power distribution box.
Cut the tape and run the wire to the front of the power distribution box. It will attach to the left post (M6 stud).

The ring terminal for the 12 volt lead for your 7-Way trailer connector is on the left of the power distribution box, taped to a harness beneath the power brake booster. Cut the tape and run the wire to the front of the power distribution box. Attach it to the right post (M8 stud).

Tighten down the ring terminals using the proper sized nuts. To activate the brake controller power post, insert a 30 amp fuse into the corresponding slot in the power distribution box. Activate the 12 volt power by inserting a 40 amp fuse into the corresponding slot. Reassemble the power distribution box covers and you are done.

I have included a link to an FAQ on this procedure below. The part you need is near the end called Finalizing Connections for the Brake Controller.

expert reply by: Michael H