Troubleshooting Flat-Towing Wiring Harness HM56203 for 2005 Jeep Liberty

Question:

I have a HM56203 installed on my 2005 Jeep Liberty. Running lights working, but brake and turn signal are not. Any suggestions?

asked by: Ray

Expert Reply:

First, make sure that all connectors for Hopkins 4-pole wiring harness # HM56203 are fully-seated together at the Liberty's tail lights and that the locking clips are engaged. Next, check the white ground wire to be certain it is tightly affixed to a clean bare metal spot on the car's metalwork. Sand off primer/paint and/or clean off any other material or contaminants that might prevent metal-to-metal contact. This ground wire is most often the cause for lighting issues like yours.

You can also disconnect the harness and reconnect the OEM wiring to confirm that these light functions are working properly on the vehicle itself, independent of the towing harness. If not you may have a blown fuse.

Once you get things working you can protect those connections with dielectric grease like # 11755. This grease prevents entry of moisture and dirt that can cause corrosion over time.

expert reply by: Adam R