Why Would Proportional Brake Controller Constantly Show that Trailer Brakes are Being Applied

Published 12/27/2016

Question:

I have this controller and it is applying the brakes going up hill on its own. Numbers just start counting up and slowing the truck to a crawl.

asked by: Terry

Expert Reply:

Sounds like the stoplight circuit (red wire) of the brake controller has voltage on it at all times and that is telling the controller to be constantly looking for deceleration and to apply the trailer brakes. You need to make sure the red wire isn't shorting out to the black wire which carries the 12 volt power circuit as that is most likely the problem.

expert reply by: Jameson C