Troubleshooting One Electric Trailer Brake That Locked Up While Driving on Interstate

Updated 06/02/2015 | Published 06/01/2015

Question:

Today one of my trailer brakes locked up right front and shredded my tire on the interstate. Iv had the trailer two years and no problem then today it just locked up and wouldnt let the one tore go till I unplugged it . Any ideas why?

asked by: Maxine H

Expert Reply:

It sounds like there could be a short in your trailer wiring for one of the brakes or there could have been a mechanical failure in that one brake assembly. I think the second possibility is more likely since only one brake was affected.

You will want to inspect the wiring to the affected brake (and the others too) to check for signs of damaged wires or worn insulation that could cause a short. If the short were very near the one brake assembly then that might cause the issue to be isolated to the one brake. Also check the trailer and vehicle connectors for signs of corrosion.

You'll also want to pull the hub and inspect your bearings and the drum surface for any signs of mechanical damage. It is possible a foreign object found its way into the brake, or that a spring or other mechanical component has failed. Check the bearings for damage from heat - look for any obvious damage as well as to discoloration from excessive heat and replace components as needed.

You can also test the affected brake by applying 12V power directly to its wire leads to see if it engages and releases properly. The brake magnet itself can also be tested for proper operation by following the procedure noted in the linked article.

expert reply by: Adam R