Troubleshooting Newly Wired Trailer Lights With Right Side Not Working

Updated 05/13/2019 | Published 05/11/2019

Products Featured in This Question

Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End

(745)

$15.54

Hook Probe Circuit Tester

(66)

$14.36

Question:

I had the right trailer light was not working wiring was showing bare and smashed wires at the plug so I replaced the wiring harness and the lights. After replacing the left side working fine right side still not working. Mind boggling, I even tried hooking to my new truck and same problem

asked by: DAVID F

Expert Reply:

It is likely there is a ground connection issue with that right side tail light. Often that ground connection is made through the mounting hardware so you want to make sure you have a clean bare metal connection. Use some sand paper to confirm the bare metal connection prior to reinstalling ground wire or mounting hardware.

If that doesn't solve your lighting issue then use a circuit tester like # PTW2993 to test your wires an confirm the functions are getting to that tail light. If not, then trace your wire checking for shorts, crimps, etc. If there is power using that circuit tester all the way to your tail lights and they still don't work after establishing a clean ground then check the bulb if on incandescent light. You can test either LED or Incandescent lights running a jump wire from your battery to determine if the light itself is bad. If you aren't confident in your ground, you know the left side is working so you can run a jump wire from that ground location to ensure a good ground.

expert reply by: Jason S