Installing Aftermarket Brake Controller on 2012 GMC Sierra With Factory Integrated Brake Controller

Updated 07/18/2012 | Published 07/15/2012

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Question:

Your videos show installing a P3 in Gm trucks. If the factory integrated brake controller is installed, is anything else needed? I have read about running a blue wire to the bumper. Is this required only with factory integrated brake controller. I just bought a 2012 GMC 2500HD an will be towing an Airstream with electric/hydraulic brakes. I understand the GM controller wont work. Can I buy a P3 and solve this problem. Thanks allot.

asked by: Ron C

Expert Reply:

If the vehicle has the factory installed integrated trailer brake controller (ITBC), the tow package wiring that exists under the dash is used to install an aftermarket controller. The wiring is located under the dash, above where the driver's left knee would be. Look for a wiring harness with a white tag on it.

The red/black tow package wire connects to the black controller wire
The white tow package wire connects to the white brake controller wire
The light blue tow package wire connects to the red brake controller wire.
The orange tow package wire is NOT needed, cap off the end and bundle the wire up out of the way.

The dark blue tow package wire is NOT used. Instead, take the dark blue brake controller wire exiting the rear of the controller and extend it with a length of 12 gauge wire (part # 12-1-1) and run it through the firewall and under the vehicle to the rear bumper. Behind the 7-way trailer connector at the rear bumper, remove the wire loom from the wiring harness that feeds the 7-way connector behind the rear bumper. Locate the blue wire, and sever it about 6 inches behind the connector. Take the wire that you ran from the brake controller, and attach it to the blue wire that attaches to the trailer connector. The remaining portion of the factory installed blue wire should be capped off and taped up out of the way so it cannot short out on anything under the vehicle.

There will be two connections that need to be made under the hood. The power feed wire for the aftermarket brake controller is located between the under hood fuse box and the fender. Look for a wire with a large ring terminal on the end of it. The 12-volt accessory power feed to the trailer connector will also need to be connected (if it has not been already). This wire is located under the brake booster, and also has a ring terminal on it. These wires will connect to the power studs located on the forward side of the fuse box. The photo I have edited shows the locations of the wires and the power studs.

I have linked you to a Technical Bulletin we received from Tekonsha that runs through the whole process for you. To see the bulletin, click on the provided link. I have also linked you to an install video that will help you find the tow package wiring under the dash, as well the necessary wires under the hood that will need to be connected to the fuse box.

Other than the brake controller, the length of wire, the butt connectors and # DW05450 heat shrink tubing to protect your connections, you will not need anything else to bypass the factory brake controller and install the Tekonsha P3. The Prodigy P3 is compatible with electric over hydraulic braking systems.