Installing Brake Controller and Trailer Connector on 2003 Chevy Blazer

Expert Reply:

Your Blazer is not prewired for a brake controller, but one can be installed using our Brake Controller Install Kit, part # ETBC7. The kit contains everything necessary to install a controller, including the 7-way connector. The 7-way connector included in the kit is actually an adapter meant to be plugged into an existing 4-pole trailer connector, but the connector on the adapter could be cut off and directly wired to the existing wires you located near the spare tire.

The white wire on the adapter would attach to the white wire on the under the vehicle, the green wire on the adapter would connect to the dark green wire under the vehicle, the yellow wire on the adapter attaches to the yellow wire under the vehicle and the brown wire on the adapter would connect to the brown wire under the vehicle. This leaves 4 wires remaining. The light green wire under the vehicle would attach to the purple wire on the adapter. The black adapter wire would be used to provide power for any trailer mounted accessories or batteries that would need to be maintained. This black wire would be connected to the black wire in the duplex cable included in the install kit, and would be ran to the front of the vehicle and attach to the positive battery terminal via a 40 amp circuit breaker also included with the kit. The blue wire on the adapter carries the output voltage from the brake controller. This wire would be connected to the white wire in the duplex cable and would ultimately connect to the blue wire exiting the rear of the controller.

For a brake controller, I would recommend the Tekonsha Prodigy P2, part # 90885. This is our best selling controller that is very easy to use. The controller is typically mounted under the dash, to the right of the steering column. It should be within easy reach of the driver. The controller will have 4 wires exiting the rear. The black wire connects to the positive battery terminal, via a 20 or 30 amp breaker included in the install kit. The brake controller instructions will state which breaker should be used. The white wire would ground to the negative battery terminal, and the blue wire will connect to the white wire in the duplex cable that was ran from the rear of the vehicle. The red wire will connect to the cold side of the brake stoplight switch, which is located under the dash at the top of the brake pedal. The switch could potentially have several wires coming off of it, use a circuit tester like part # 3808 to locate the wire that only shows voltage when the brake pedal is pressed.

We have several resources on the website that can assist with the installation, as well as an install video. The video shows the install kit being used on a different vehicle, but the procedure on your Blazer would be identical. To see the FAQ pages and the video, use the links provided.

expert reply by: Mike L