Troubleshooting Taillight and Brake Light Circuits Not Active on Trailer Wiring

Question:

We can get some of the lights to work, but not all of the lights. The turn signals, backup, and emergency flashers work, but the taillights and brake lights dont

asked by: Carol W

Expert Reply:

Based on what you described it sounds like your trailer wiring has a weak ground and when you try to use the circuits that draw the most amperage the lights stop working. This is pretty common. What you can do is try improving the way the lights ground or run a jumper wire from the lights back to the main ground circuit of the trailer wiring and then the circuits should start working.

I attached a help article on troubleshooting trailer wiring with more info for you to check out as well.

expert reply by: Jameson C