Which Tow Package Wire on 2012 Ford F350 Carries Brake Controller Output
Published 11/09/2019
Question:
I have 2012 ford f350 does the blue or red wire output to brakes. I have red hook up now and blue to nothing. Brakes works a little when sliding controller or engaging brake pedal. Should I change to blue. and what happens to red. thank you
asked by: Gary D
Expert Reply:
In the tow package wiring bundle, the red or orange wire carries 12 volts from the battery to the trailer. Many use it to keep a maintenance charge on a trailer mounted battery. The blue wire carries the output from a brake controller. This assumes everything is installed correctly.
You can test this by using a circuit tester like # PTW2993 on the blue wire that exits the rear of the controller. You should see voltage on that wire with the manual brake switch on the controller activated. You won't see any output with the brake pedal unless your controller is the time-delayed type.
I've linked you to a help article that explains several troubleshooting strategies for brake controller installations.
