Troubleshooting Trailer Brake and Turn Signal Not Functioning

Question:

The left blinker and break light on my trailer are not working. I know that the yellow wire operates these and it is hot coming from the truck and the trailer when I tested them. When I connect the yellow trailer wire to the yellow light wire it goes cold and does not work, same with the breaks. I sanded down a small area to ensure the ground is good. I also checked the fuses in my truck for the left blinker and they are good. I also tried another light and had the same problem. Any idea why the connection would go bad when connecting the two wires? thanks

asked by: Eric V

Expert Reply:

There has to be a short on the wiring for that circuit which is causing it not to function. That would explain why there is voltage present on the vehicle connector but none at the light and you know the ground is good. You'd want to go over the trailer's wiring looking for any shorts and fix as necessary.

expert reply by: Jameson C