Troubleshooting Vehicle Turn Signals After Wiring Harness Installation

Updated 04/02/2018 | Published 03/30/2018

Question:

I installed the trailing wiring harness on my 2008 Saturn Vue recently, and now the drivers side turn signals have stopped working. The dash indicator for the turn signal is blinking rapidly, as if the bulbs was blown. However, I replaced the bulb and I still have the problem. The front side bulb is working, just not blinking with the turn signal on, but the rear bulb does not light up at all. I disengaged the wiring harness and plugged the vehicles own wiring back in, bypassing the wiring harness, and it did not correct the problem. When I plugged the wiring harness into the trailers lights immediately after installing the harness, the trailers turn signals seem to be working properly. Ive also checked the fuse for the turn signal located adjacent to my cars battery, and it seems to be fine, as well. Any suggestions as to what else could be going on? Thank you.

asked by: Donna M

Expert Reply:

Thank you for your purchase of Curt trailer wiring harness # C56026.

The two most likely issues that could cause your lighting problem are a weak ground or bent contacts inside the driver-side vehicle tail light connectors.

The main white ground wire for the harness must be affixed to a clean bare metal spot on the vehicle; even primer and paint can interfere with a solid ground. Bad grounds can cause all sorts of weird behavior from trailer wiring. You can sand off the paint from the grounding point t provide metal-to-metal contact.

The other likely issue is that one of more of the electrical contact pins inside the connectors, either the connectors on the vehicle or on the harness, are bent slightly and not making proper contact. Inspect all the pins looking for a bent one or even foreign material or water trapped inside.

You can also refer to the linked troubleshooting article for more information.

expert reply by: Adam R