Troubleshooting Brake Controller Output that Causes AC Fan to Run

Published 12/21/2021

Question:

I have a 2006 Chevy Silverado 2500HD LT. When the trailer brakes on my travel trailer are plugged in and the brakes are applied the ac fan starts running. The more voltage applied to the breaks the faster the fan runs. If I turn down the voltage on the brake controller it slows down.

asked by: Daryl B

Expert Reply:

That is really an odd situation but what's going on is that your brake output circuit is some how ran or shorted to your AC fan power wire. Not sure how that happened but you have a short between those two circuits that you'll need clean up. Most likely it's cut or exposed wire between the two circuits that needs to be insulated.

expert reply by: Jameson C