How to Install Brake Controller On 2007 GMC Yukon

Published 01/09/2016

Question:

My 2007 YUKON SLT came with factory 7-way round connections at the hitch, but the wiring harness under the dash did NOT come with a connector installed, but rather just a loop of wires taped underneath with a tag stating it was the trailer connection harness. The COLORs of the harness are a little different than those on the Agility unit, so can you help me determine which color wires on the harness connect to which color wires on the Agility controller? The wires preinstalled in the truck are: thin white approx 20ga thin pale blue with white stripe approx 20ga heavy red with black stripe approx 14ga? heavy blue approx 14ga? Also, is there any additional wiring or connections that have to be made directly at the fuse panel for this vehicle? The counter staff where I purchased the controller seems to have different information for each person I have talked to about it.... Thanks

asked by: John

Helpful Expert Reply:

I'd be happy to assist you with that. For the 2007 model year, GMC didn't use a connector for the tow package wiring under the dash, just bare wires as you've stated. The existing wires would connect to your brake controller as follows:

Red tow package wire to black brake controller wire
Dark blue tow package wire to blue brake controller wire
Light blue/white striped tow package wire to red controller wire
White tow package wire to white controller wire

Since you have the factory 7-way trailer connector at the rear bumper, there shouldn't be any other connections that need to be made, but in some cases there will be two wires under the hood that need to be ran to the fuse box. This is fully explained in the FAQ article I've linked for you. I've also linked you to an install video showing a different controller being installed on a 2007 Yukon. The procedure shown would be the same as your vehicle.

expert reply by: Mike L