bing tracking image
Q & A Icon

How to Test Brake Controller without Trailer Connected


How to check unit without a trailer. 96 chev.


Expert Reply:

All the brake controller needs to sense a trailer connection so that you can test it is a slight amperage draw on the output circuit. For that you can use a circuit tester like the part # PTW2993 with one pin grounded and the other on the output pin. Then you can hit the brake pedal of the vehicle and you should see the brake controller operate like normal. You'll need someone to help since it's hard to be at the rear of the vehicle and pressing the brake pedal. If you can't get the controller to operate normally there is a more in-depth way to test it.

Testing the brake controller is fairly easy. 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 the Quickee Tester, part # 3808, 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 farther back either in 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 before the brake pedal is pressed you have connected the red wire from the brake controller to the wrong circuit. You would then need to find the brake switch wire that has power ONLY when the brake pedal is activated.

If 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.

expert reply by:
Jameson C

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>