Troubleshooting Brake Controller That Works Intermittently

Updated 06/15/2026 | Published 06/10/2026

Question:

Brakes were fine when we left home. Stopped for fuel after 150 miles, trailer brakes not working. Got to RV park and set up. Next morning, got 3.75 -4.0 volts at connector on truck when brake pedal depressed. Next morning when we left, brakes worked fine. A couple hours down the road, not working. 2014 Silverado 2500 Diesel. Got any ideas?

asked by: Wayne

Expert Reply:

Hey Wayne, have you checked any of the pins of your trailer wiring for corrosion? Usually this issue is an intermittent connection due to corrosion or a bent pin which you can easily address if you inspect the pins of the 7-way and fix as needed.

expert reply by: Jameson C

Jon

6/12/2026

Experts reply is point A. I have found the ground pin or the grounding in general to be the primary culprit. Check the ground pin and do use the dialectic grease. When not in use, ( longer layups ) the socket on the vehicle and the plug on the trailer will benefit from a weather cover. Next be confident about where the ground pins are actually bolted. Be sure of a tight clean connection.

Jameson C.

6/15/2026

@Jon great tip! Thanks for passing that along!

Wayne

6/15/2026

Connectors are all okay. Plugged and unplugged several times, wiggled plug around, still no brakes. Worked fine the next day when I hooked up, quit working by next gas stop.

Jameson C.

6/15/2026

@Wayne did you check the ground wire that runs from the trailer's connector to the trailer frame? Make sure it's connected solidly to the trailer frame.