Troubleshooting Trailer Running Lights that Aren't All Powering On

Question:

Everything was attached and properly working. I paired the appropriate wires and ran it the same way on my trailer. However, now the front amber lights work, but the side reds and taillights no longer work. Any suggestions would be super helpful! Using a 4 wire harness.

asked by: Jessica

Expert Reply:

Assuming all of the clearance lights are connected properly to the running light circuit your issue is either an insufficient ground or you have too many lights on the circuit which is overdrawing it and all of the lights won't work.

Try checking the main ground circuit of the trailer which will connect from the trailer frame to the trailer connector. Make sure it's making a solid connection and then also check to make sure all of the lights are grounding to either the trailer frame or back to the main ground circuit of the trailer wiring.

If the trailer has several running lights you can lighter them amperage load by converting them to LED as they draw considerably less than incandescents. I attached a link to a page that has all of the LED trailer lights we offer plus a link to a page that has some trailer wiring troubleshooting as well.

expert reply by: Jameson C