After Installing New Trailer LED Tail Lights the Lights Will Not Light Up

Question:

I took out off my old set of lights on my trailer purchased submersible ones . Connected them up and they do not work. Am I missing something here or what ?

asked by: Tim

Expert Reply:

This could be a ground issue. Without a proper ground the circuit cannot be completed, and the lights will not work. The light grounds should 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.

It is also possible that the vehicle trailer wiring is not rated for use with LED lights. Use a circuit tester such as # PTW2993 to make sure power is getting back to the wiring at the lights on the trailer. If it is then you likely will need load resistors, such as # DI34ZR, installed in line on the affected circuits.

If there is no power at the wiring at the back of the trailer, then there is an issue further upstream. Make sure all of the wiring is intact from the front to the back and fix any breaks or pinched wires as needed. Make sure the trailer and vehicle side connectors are clean and free of corrosion inside and out.

To test the vehicle side wiring, if applicable, you can follow the help article I have linked.

expert reply by: Michael H