Troubleshooting Brake Controller that Reads 0.0 Occasionally When Brake are Applied

Published 03/05/2015

Question:

I have a 2002 Silverado. The brake controller shows 0.0 when the brakes are applied. Without the trailer hooked up. Doesnt do it all the time.

asked by: Dan G

Expert Reply:

Normally if a brake controller is reading 0.0 when the brakes are applied that just means that the gain of the controller is adjusted all the way down. You may just have to turn the gain of the controller up. The fact that it only does occasionally might imply that it's a loose wire for the controller or there is corrosion on the 7-way that needs to be cleaned off.

Otherwise, it is hard to know exactly where the problem lies, but the first thing I would check would be to test the manual override lever when the trailer is connected and see if it will apply the trailer brakes. If it does have voltage then I would check to make sure brake switch circuit (red wire) sees voltage when the brakes are applied. If not, then you have located the problem and will need to inspect this wire for loose wires or corrosion and fix as necessary.

The next thing to test will be the brake output circuit (blue wire) from the brake controller. The easiest way to test this will be to cut the wire and then test for voltage on the side from the brake controller with the manual lever applied. If you get voltage here then you know that the problem lies somewhere in the wiring between the brake controller and the 7-way trailer connector. At this point you will want to start by testing the trailer connector for voltage on the brake output circuit of your 7-way, this should be the blade in the 5:00 position. At this point you will need to work from there back to the front of your vehicle on this circuit checking for voltage until you find it. Once you have found voltage you will have narrowed down where the problem is. You will need to look for any loose or exposed wire and corrosion and fix as necessary.

You might also try setting up your brake controller again just to make sure something is not just out of adjustment. I attached installation instructions for this product for you to check out also.

expert reply by: Jameson C