Troubleshooting Trailer Brakes Still Activating When Blue Wire On Controller Is Cut

Question:

I have an 2012 international 4300 that the electric brake controller only works full power. I can’t adjust the gain and get the brakes to not lock up. The light doesn’t work and I cut the blue wire to check controller and the brakes still work.

asked by: Kyle G

Expert Reply:

If your trailer brakes are still activating after you cut the blue wire from your brake controller then there is a wiring short inside the wiring either on your 2012 International 4300 or on the trailer. Since the brakes are only activating when you press the brakes you short is likely between the brake light wire and the brake actuator wiring.

You can use a Test Light # PTW2993 will allow you to test the connectors on your International to determine if the issue is with your truck or the trailer. I have linked an article below that will help you with the wiring for both.

expert reply by: Bud M