Troubleshooting Trailer Running Lights that Turn Off after 3-5 Seconds

Question:

I purchased a harness c59236, and had it installed it in my 2006 Passat. All of the connections check out fine on my circuit tester. However, the running lights brown wire, immediately next to the white ground on the connection to the trailer act oddly when I turn on the cars rear lights, the trailer running lights come on for about 3-5 secs, and then go out. Al the other circuits flasher, brake, etc. are working great. I know the trailer is working fine, because its AOK when I hook it up to another vehicle. Any thoughts on what this might be? Thanks

asked by: Kirk M

Expert Reply:

It's possible that you are drawing too much amperage on the running light circuit of the part # 118562 that you installed. The running light circuit can only draw up to 7.5 amps so if you have a lot of running lights/clearance lights on your trailer you could be asking too much of the converter box.

First thing I would try is finding a new place for the ground circuit of the harness. Improving the ground could potentially help as well.

If you test the running light circuit of the 4-way on your vehicle, does it show 12 volts? If so, then that would be a pretty good indicator that you are drawing too much. Going with LED trailer lights might be your best solution since they draw much less than incandescent lights. I attached a link to a page that has all of the LED lights we offer as well as a couple help articles for you to check out.

expert reply by: Jameson C