Turn Signals Cause Brake Controller in a 1997 Ford E-350 Van to Power Trailer Brakes
Question:
I have a 97 E350 that I installed your brake controller and the simple plug harness from controller to truck harness. the stock harness was modified at some point and is only being used for power and ground to the controller. the blue break wire is hardwired direct from brake controller to the 7 pin connector. the red wire is hardwired direct into the brake light side of the brake switch not the hot side. when applying the brakes everything works like it should with no issues. But when I turn on the signals the trailer brakes engage pulsating to the signals. what do I have to do to make this go away
asked by: Dan
Expert Reply:
You have the red wire connected to the wrong brake switch wire. There is more than one wire on the cold side of the brake switch that will have power when the brake pedal is pressed. One of the wires can show power with the turn signals or head lights on. This is likely the wire the brake controller is attached to so it applies the trailer brakes when the turn signals are on.
Use a circuit tester such as # PTW2992 to test the brake switch wires to find the one that has power only with the brake pedal and not when the turn signals or head lights are on. Once you find the right wire just make a new connection to the brake controller red wire and you should be good to go.
