Troubleshooting Trailer Lights that Shut off When Vehicle Brakes are Applied

Question:

I hook up the tailer to the 2007 silverado and all the lights work good until I hit the brake pedal. The lights on the trailer go out when the brake pedal is applied. Checked the wiring and its all new on the trailer. Made sure the lights were hooked up right a d they were. What makes the lights go out on the trailer when I press the brake pedal?

asked by: Curtis L

Expert Reply:

Typically when trailer lights all cut out when a certain function is applied like the vehicle brakes the problem is either a bad ground for the trailer light assemblies or you are overdrawing the trailer light circuit. Most likely its the ground.

First place to start would be to inspect the trailer wiring connector on your 2007 Chevy Silverado. Look for corrosion on the pins. Clean as necessary. Most trailer lights ground through the mounting assemblies. Since your trailer is brand new I wouldn't suspect corrosion, but I would still check to make sure they are connected to a clean metal surface. You should also check the main ground of the trailer wiring that goes from the connector to the trailer frame.

Another possibility is that your trailer is aluminum, since aluminum isn't a good conductor I would recommend you run a ground wire from each of the assemblies to the main ground of the trailer in this situation.

If your trailer has a ton of lights on you could be overdrawing your trailer light circuits. An easy solution to this would be replace your trailer lights with LEDs as they draw considerable less. I attached a page that has all of the LED trailer lights we offer.

I also attached a link to an FAQ page on troubleshooting trailer wiring.

expert reply by: Jameson C