Troubleshooting No Left Side Trailer Lights When Connected to Curt Wiring on a 2004 Jeep Wrangler

Updated 01/17/2023 | Published 01/16/2023

Question:

2004 Wrangler TJ All of my rear lights are fully functional, but when I tie a harness into them the left side lights on the trailer do not work. The lights on the Jeep still work. I have used two different Curt harnesses.

asked by: Tim C

Expert Reply:

Have you tested the 4-Way of the Curt T-Connector Vehicle Wiring Harness # C55363 for your 2004 Jeep Wrangler apart from the trailer, or do you just connect the trailer and see an issue?

If the problem is only occurring when the trailer is connected to the Curt harness then I recommend testing the Curt 4-Way to make sure it has all of the functions. If it does then your problem is likely a bad connection or damaged wiring somewhere along that circuit. If you apply direct 12V power to that trailer wiring circuit then it may be powerful enough to jump a damaged wire and that's why you're seeing this scenario.

Hope this helps out, let me know if you're still needing troubleshooting help!

expert reply by: Jon G