Brake Controller Works with Manual Override but Not with Brake Pedal

Updated 09/18/2018 | Published 09/17/2018

Question:

I bought a 2nd brand new controller and a 2nd brand new wiring adapter and replaced my whole setup. However, the 2nd one acted just like the first. When I pushed down on the brake pedal, nothing. When I engage it with the manual slide, it works fine. The 1st controller worked perfectly for a year and then the issue started. What could have happened? I also may have lost my brake lights although I have not confirmed this yet as I just noticed nothing lighting up when I looked in the side view mirror when it was dark. Also do not know the timing - whether issues happened at same time. Only mentioning this just in case it speaks to you. Thank you!

asked by: Rick

Expert Reply:

Most likely you have a blown stop light or CHMSL fuse on the tow vehicle. Consult the vehicle owner's manual and/or the legends on the fuse panel lids to find the locations of stop light/CHMSL fuses to check them. If the brake controller red wire is not showing any power when the brake pedal is pressed then it will not send power back. The manual override works independently of the brake pedal which is why the controller works fine when the override is used.

expert reply by: Michael H