Troubleshooting Trailer Lights Blowing Trailer Running/Parking Light Fuse On Different Vehicles

Question:

I have an aluminum trailer and the fuses in my truck keep blowing. I checked the ground in the trailer hitch connector and it tests okay. The fuses typically blow when the trailer is connected to truck and I start the truck. Its the running/parking trailer lights that blow the fuse. I have rewired all the running lights and replaced all with LEDs hoping that would solve the problem but no luck. The fuses are still blowing both on my truck and a friends car when he borrows my trailer. I read in one of your posts that the ground connections to the trailer should be clean connections free of corrosion. Since its aluminum that seems to corrode quickly, should I try running a ground wire to each of the running lights?

asked by: Carl

Expert Reply:

I recommend checking the trailer connector for a short. There may be a pinched or torn wire in the connector. A blown fuse is typically caused by a short somewhere in the wiring. Since you say you've rewired the trailer, the short may be in the trailer connector.

A ground issue does not typically cause a fuse to blow. For the best trailer ground, I recommend running the light grounds back to the main trailer ground.

expert reply by: Victoria B