Troubleshooting Trailer Brake Lights that Only Flash When Brakes are Applied

Published 11/20/2018

Question:

I bought a enclosed trailor. I have a 02 toyata truck. When i press the brakes my trailor brake lights flash then immediately go back to the tail lights. Brake lights will not stay litt up. Everything else works fine. Thanks

asked by: Jason

Helpful Expert Reply:

Try improving the connection of the main ground wire of the trailer wiring harness. Make sure it is attached to a clean metal surface. Or you can run all of the trailer wires back to the main ground. This is actually the ideal solution. But you can also check the current grounds for the lights to make sure they are making a solid connection to a clean metal surface.

What you described could be an insufficient ground scenario so finding a way to improve the grounds will hopefully fix the problem. I attached a help article on troubleshooting trailer wiring for you to check out as well.

expert reply by: Jameson C