Troubleshooting Curt Trailer Wiring Harness Installed on 2010 Hyundai Tucson

Updated 03/19/2014 | Published 03/16/2014

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(89)

$67.00

Hook Probe Circuit Tester

(70)

$14.49

Question:

When I plug a trailer to my car the left side running lights of my vehicle turn off. recently I have also had one side of the running lights stay on when my vehicle is off and not trailer connected to it. I have made sure it is grounded. could the lights turning off be from the trailer trying to draw to much amps, and why would my lights stay on if the car is off. I have pulled the fuse from the power line to the converter and this has fix the lights being on.

asked by: Kenny

Expert Reply:

Unless your trailer is unusually well lit, the # C56348 wiring harness should have plenty of capacity.

From your description, it sounds like your converter has an internal short that is allowing the 12-volt feed from the battery feed back into the vehicle taillights. You can confirm this by using a circuit tester like part # 40376 on the inputs of the converter. With the vehicle shut off, you should only see power on the 12-volt battery feed. If you find power on any of the other wires, you have confirmed that the converter is faulty and should be replaced.

If you confirm that the converter is shorted, before replacing it you will want to closely examine your trailer wiring to ensure there are no wiring problems that caused the converter to short out. Begin at the trailer connector, making sure the connector is not damaged. Trace each circuit rearward to its lamp, checking for loose connections or wire with worn or cracked wire insulation and repair as necessary.

If you should need to replace your converter, we have a plug-and-play option you might be interested in, part # 118501. Instead of splicing into the existing wiring, the # 118501 plugs inline into the factory connection at the rear of the taillight assemblies for a much simpler installation.

I have linked you to our trailer connector troubleshooting article, as well as to an installation video for the # 118501 wiring harness I mentioned.

expert reply by: Mike L