Troubleshooting Brake Controller Installed On Chevrolet Truck Locking Up Trailer Brakes

Question:

Im troubleshooting for a friend that has a chevy pickup with a horse trailor that has a breaking system allready connected not sure which unit he has though. I found a cequent number p00208181 if that helps any. when applying even moderate breaking his trailor tires are locking up . what do we do to adjust things. do i need more info to better describe my problem?

asked by: Brad H

Expert Reply:

The first thing you can do is test the wiring connections for the brake controller on your friend's Chevrolet truck.

Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like part # PTW2993, you should get output to the controller side of the wire you severed. If the manual slide activates the trailer brake output wire properly, try the brake pedal. If the brake pedal activates the brake output properly also then the problem is either the vehicle wiring or on the trailer.

If either the brake pedal or the manual slide are not functioning properly you will need to test the wires going into the brake controller. Make sure you have power entering the brake controller on the black wire. On the red wire you will only want power when the brake pedal is pressed.

If there is power on the red wire without the brake pedal pressed you have the red wire from the brake controller attached to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated. This switch is found at the top of the brake pedal.

If all these connections check out and the brake controller is properly grounded then there is possibly a problem inside the brake controller.

I am including a link to a video that will show you how to test the wiring on a brake controller.