Installing Tekonsha P-3 Trailer Brake Controller # 90195 On 1994 GMC Sierra

Question:

what color is the wire on the brake light switch going to the brake lights. thanks

asked by: Gene V

Expert Reply:

The wire from the Tekonsha P-3 Trailer Brake Controller, part # 90195, that connects to the brake light switch is Red.

To determine which wire you will need to splice into on your 1994 GMC Sierra, you will need to use a circuit tester, part # PTW2993. You will need to connect the red wire from the brake controller to the wire that only has signal when the brakes are applied. If you have trouble finding the stoplight switch wire, you can splice into the Center High-Mount Stoplight wire.

In addition to the P-3 Brake Controller, you will need to install Tow Ready Custom Fit Vehicle Wiring, part # 118315. You would then need to install a brake controller installation kit # ETBC7, which will give you a 7-Way connector at the rear of your truck.

The 4-Way Connector of part # 118315 will plug into the adapter included with the # ETBC7 kit and then you will need to connect the remaining wires. The White wire is the ground and should be connected to the frame of vehicle. The Black wire will be connected to the Black wire inside the duplex cable and ran to front of vehicle and connected to the positive battery terminal via included 40 amp circuit breaker. The Blue wire will be connected to the White wire inside the duplex cable, and ran to the front of the vehicle and later will be connected to the brake controller. The Purple wire can be connected to the reverse lights if the trailer has reverse lights or can be taped off and tied out of the way if not being used.

To wire the Tekonsha P-3 Trailer Brake Controller, the wires on the back of the brake controller will need to be hard-wired. The White wire will be connected to the negative battery terminal. The Black wire will be connected to the positive battery terminal via 20 or 30 amp circuit breaker, as specified in brake controller instructions. The Blue wire will connect to the White wire in the duplex cable that you ran up earlier. As mentioned before, the Red wire will be connected to the stoplight switch near the brake pedal.

I have linked instructions for the Tekonsha P-3 Trailer Brake Controller, part # 90195, the 4-Way wiring # 118315, and the # ETBC7 installation kit. I have also linked an FAQ Article on installing a brake controller from scratch that you may find as a good reference.