Troubleshooting Trailer Light on Fender Not Functioning

Published 03/30/2020

Question:

I have a 2011 Wells Cargo MPT 461 with factory led lights all around. My issue is with my right taillights on the right fender and the back of trailer. The left side lights all work as they should but the right sides won’t function at all. My plug in taillight tester for my 2008 Ford Edge AWD indicates that things are working fine on the vehicle side but trailer will not function on right side at all. What could be a solution to this problem.

asked by: Tom C

Expert Reply:

Most likely there's a bad ground on the trailer lighting assembly that's not working or there's some corrosion on the pins of the 4-way which is preventing the circuit from functioning. Try cleaning the pins first with sandpaper and then go over the wiring looking for any obvious issues like cut/exposed wire and then make sure the assembly is grounding like it should.

I also attached a couple helpful articles on trailer wiring for you to check out as well.

expert reply by: Jameson C