Trailer Wiring and Brake Controller Installation on 1995 Chevy C/K 3500


Chevy 3500 Truck. I have a 4 prong flat at the back of the truck. I need to pull a trailer with electric brakes. The only wires I have at the back of the truck is the Brown, yellow, white small and black. I do not have any of the large wires at the back of the truck. I need to know what I need where to hook in the large wires on the truck so I can use a tekonsha controller and the reverse lights. Thanks

Expert Reply:

Your best bet to install a brake controller would be to use our Brake Controller Install Kit, part # ETBC7. The controller includes everything necessary to install a brake controller, including an adapter to convert the existing 4-pin to a 7-way. Due to the length of the truck, you might need an extra 10 feet of the duplex cable, part # 10-2-1.

The adapter plugs into the 4-pole, leaving 4 additional wires. The blue and black wire will connect to the 2 conductor cable (see instruction link). The blue adapter wire connects to the white wire in the cable, and the black adapter wire attaches to the black wire in the cable. The cable will be ran under the vehicle to the engine compartment. The white adapter wire grounds to the vehicle frame, and the purple wire would tap into the circuit feeding the reverse lights.

Once the cable reaches the engine compartment, the black wire connects to the positive battery terminal via the 40 amp breaker included in the install kit. The white wire runs through the firewall and will connect to the brake controller.

The controller itself would mount under the dash within easy reach of the driver, preferably to the right of the steering column. There are 4 wires exiting the rear of the controller. The black wire supplies power to the controller, and would pass through the firewall to the positive battery via a 20 or 30 amp breaker that is also included with the install kit. The instructions that came with your brake controller will explain which breaker to use. The blue controller wire connects to the white wire that was previously ran through from the rear of the vehicle. The white brake controller wire will connect to the negative battery terminal. The red wire connects to the brake stoplight switch circuit. The stoplight switch is located at the top of the brake pedal. There will be several wires exiting the switch, you will need to use a circuit tester like part # 40376 to locate which circuit shows current only when the brake pedal is pressed. Once the correct wire is located, tap the red wire into it. The extra length of cable can be used to lengthen the wire runs to the battery as needed.

I will provide links to some FAQ pages as well as an installation video that you might find helpful.

expert reply by:
Michael L

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