Electric Break Control

Luremaker · Oct 8, 2004

My electric trailer break control on my P/U does not seem to be working. Does anyone know of a method of testing it?
Thanks Steve

Warwagon · Oct 8, 2004

First I would check the fuse for the brake controller, if that is good then check the pin in the truck end of the trailer wiring harness, if that is good, work your way down the harness going from the trailer tongue to the brakes. Oh yea, make sure you have a good ground connection between truck and trailer. Kevin

jdcook00 · Oct 8, 2004

Depending on what kind of controller you have, it may not have output without a trailer hooked up. But you can check some circuits. Power to controller (usually a red wire) should have 12 volts with the key on. Brake pedal input (green wire) should have 12 volts with brake pedal depressed. Ground to controller (white wire) should be a good clean ground. Controller output (usually a blue wire) should have voltage when the controller is activated. Voltage will vary depending on how the controller is set (gain). There may be another wire that would be for illumination but most don't use it.
Hope that this helps. /forums/images/graemlins/smile.gif

GaryK · Oct 9, 2004

If you have a GM truck, there are two sets of fuses to check, one under the dash, the other under the hood. The one under the dash is for the special harness that comes with most new trucks for a controller.