Troubleshooting Trailer Brake Controller Connection Error Message in 2008 Silverado

Question:

Hello. My 2008 Silverado 2500HD brake controller is saying short in system no trailer brake. Where would be good starting points to troubleshoot problems?

asked by: Jeff A

Expert Reply:

This kind of brake circuit warning can have several causes, from corroded contacts in the truck socket or trailer plug to a damaged wire or even just a wire that might be rubbing on the truck or trailer frame. Since your truck is a couple of years old I would start with the corrosion check. You might want to get a can of aerosol electrical contact cleaner like Caig De-Oxit.

To first narrow down the problem to either the trailer or truck, disconnect the trailer plug and apply direct 12V battery power to the trailer plug ground and brake contacts. Please see the photo. If you hear the brake magnets hum as they should this tends to suggest the problem is on the truck side and you can move your efforts there.

Carefully inspect the condition of the brake circuit contact at the 5:00 position in the 7-way. Even slight discoloration can cause a connectivity problem and trigger this error message. Unplug the harness from the back of the 7-way and check it too in the same way since corrosion can start there. Trace the brake wire as far forward as you can under truck looking for cracked insulation or spots where the brake wire may be rubbing on the frame. Repair or replace any damaged wiring.

Usually these few steps will reveal the problem. If you need a new 7-way socket or trailer plug you can use parts such as # HS381-9000.

Please let me know the results of your testing and I will be glad to offer next steps as needed.

expert reply by: Adam R