Installing Hopkins Agility Brake Controller on 2007 GMC Sierra New Body Style

Question:

I have a 2007 GMC Sierra new body style. I have located the wires under the dash and the wires already run to the battery area for connection under the fuse box. All the instructions I am finding on the internet is telling me to cut the blue wire by the spare tire and you all have no instructions on here to help with the new body style. Am I going to have to cut this wire and purchase more wiring?

asked by: Erich F

Expert Reply:

Take a look at our GM truck Brake Controller Install FAQ article, which you can see by clicking the provided link.

You would connect the controller to the bare wiring under the dash, matching the wire colors as described in the article. If you do not already have a 7-way connector, you can remove the knock-out on the bumper next to the license plate and install one using # PK11916. The existing wiring harness located at the end of the drivers side frame rail or above the spare tire will have a connector on the end of it. Remove the mud/crud plug from the connector, and plug it into the rear on the # PK11916. It sounds as if you have already addressed the necessary connections at the fuse box under the hood.

The only instance where you would need to cut the blue wire at the rear of the vehicle would be if the truck has the factory integrated brake controller (ITBC). If this is the case, and you are wanting to bypass the ITBC and install an aftermarket controller, follow the procedure outlined in the Technical Bulletin I have linked to. The controller install would be identical to that shown in the FAQ article, except for the blue brake output wire. Connect the controller to the wiring under the dash, with the exception of the blue brake output wire exiting the controller. Use a butt connector and extend this wire with a length of 10 gauge wire (# 10-1-1) long enough to pass through the firewall, into the engine compartment, and under the vehicle to the trailer connector. As you route the wire rearward, be sure to avoid any hot components like the exhaust manifold and exhaust pipes or anything moving like steering or suspension components. When you reach the trailer connector, find the blue wire exiting the rear of the connector (you might need to remove some of the wire loom) and sever the wire, leaving around 6 inches of wire coming from the trailer connector. Use a butt connector to connect the wire you ran from the controller to the wire coming from the connector, and you will be good to go.

expert reply by: Mike L