Wire Colors For Brake Controller Connector on 2002 Ford F350

Question:

Previous owner cut the connector on the truck side factory brake controller harness. I have a tekonsha prodigy and appropriate harness for it. I plan to cut the tekonsha harness and directly wire it into the factory wires. Could you guide me to which wires to splice together? Thanks.

asked by: Jon

Expert Reply:

I don't have information about wire colors, but I can explain how to figure out which wire provides which function using a voltmeter or test lamp like # PTW2993. With the ignition on, one wire should show a constant 12-volts. This would connect to the black wire on your brake controller harness. Next, there will be a wire that only shows voltage with the brake pedal pressed. This would connect to the red brake controller wire. Of the two remaining wires, one is ground and the other carries the brake output to the trailer connector. Ford typically uses a blue wire for the brake controller output, so the remaining wire would be the ground.

expert reply by: Mike L