Troubleshooting Pulsing Brakes when Blinkers are On

Updated 06/24/2015 | Published 06/23/2015

Question:

I have two trailers. One is a dump trailer and it works fine, I use the dump trailer all the time and the brakes never pulsate. The other is a 1990 Dutchman I have had an intermittent issue with it since I got it used a couple of years ago. When the right turn signal or the hazards are on the brakes pulsate. Never with the left turn signal. Also, the LED indicator in the bottom right of the controller display goes out when the blinker comes on. It does not matter what the setting is on the controller, it brakes at full power when it pulsates. The same vehicle 1995 F-350 is used to tow both trailers but it only happens with the Dutchman. It is intermittent, it will happen on every trip, long or short, but happens randomly and does not seem to matter what the weather or road conditions are.

asked by: Brian H

Expert Reply:

The right turn blinker circuit of your trailer is shorting out to the brake output circuit (signal that carries the brake controller voltage) and that is why you are experiencing the pulsating.

Starting at the trailer connector on the trailer you will need to trace the wiring back from there to the brake assemblies looking for any cut or exposed wire and fix as necessary.

I attached a help article on brake controllers for you to check out as well.

expert reply by: Jameson C