Troubleshooting Trailer Wiring That Right Turn/Brake Stops Working When Headlights are On

Question:

Hello, I have 5 wires comming from the trailor side and 4 on the Jeep side. 2 wires are double wires, yellow with brown attatched and green with brown attached. I split the double wires taking the two browns and attached them both to the brown wire from the Jeep side. Then I attached the yellow and green to their same color from the Jeep side. Then of course the white. Also attached the trailor to the hitch. Test... Lights work fine, turn signals work fine, with my lights off my break lights work fine. But if I turn my lights on, then step on the break, my right side light goes off completely, while my 3rd break light and my left break light work fine. Ive changed the bulb, rechecked all the splices....what else could it be?

asked by: Dickson

Helpful Expert Reply:

You have a weak ground on the taillight assembly on the right side of your trailer.

Make sure that the trailer side connector are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

expert reply by: Jameson C