Wiring a Brake Controller Using Factory Harness on a 2015 Ford F-250

Published 08/05/2015

Products Featured in This Question

Draw-Tite Activator IV Trailer Brake Controller - Up to 4 Axles - Time Delayed

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$103.31

Hook Probe Circuit Tester

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$12.27

Question:

2015 f 250 super duty factory pig tail bc37 14a348 hook up red to ? white to ? black to ? blue to ? ford pig tail has blue , brown red ,smaller wire blue orange, an small black white

asked by: Jd

Expert Reply:

The factory Ford harness should be labeled with the functions. On the # 5504 brake controller white is ground, black is 12 volt power into the controller, red is input from the brake switch, and blue is output to the trailer brakes.

To determine the functions of the Ford harness, if it is not labeled, you can use a circuit tester such as # PTW2993. The 12-volt circuit should be hot all the time, the input wire from the brake switch will only have power when the brake pedal is pressed. One of the wires will likely have power when the headlights are on, but you will not need this wire.

To determine which wire is brake output you can use a separate 12-volt battery to apply power to the pin in the 5 o'clock position on the 7-Way using some scrap wire. Then test the wires on the Ford harness. Whichever one has power on it when power is applied at the connector is the brake output wire. The last wire would then be the ground.

expert reply by: Michael H