Troubleshooting No Running Lights on Trailer But Other Lighting Functions Are Working

Question:

I have a 2016 Ford Escape SE. Had the kit less than a year. I recently sold a trailer and purchased a new one to pull a kayak. I am having the same problem now that I did with the previous, and that is I have no running lights on the trailer, while brake and turn signals work just fine. I did the usual such as have a buddy connect to my trailer, which worked fine. I brought my car to the shop that installed it and they tested it. He said everything was fine. I check it the next day and same issue. I have also used one of those 4-way testers, and same results: no running light. However, tonight when I was at the store, I decided to try the tester again and the running light indicator was on! I got home, and it was still on. I then connected to the trailer and the running lights worked! However, I did nothing that would have caused a change. I unplugged and turned off the car. I tried it again and this time the running lights won't work, and the tester running light indicator does not light up. Could this be the convertor failing? I have no other explanation.

asked by: Jason L

Expert Reply:

In most cases when you are having a malfunction on the trailer lights the culprit is usually a grounding issue. Since the trailer running lights or clearance lights are continuously in use, a weak ground or loose connection somewhere in the wiring can cause these lights to malfunction.

Make sure to check the main ground wire for the trailer to see if there is any corrosion or if it has come loose. A poor ground will be noticed more on the running light circuit because of its constant use over turn and brake signals.

If the trailer ground has checked out and you could not see any other issues with wiring, then checking the output at the vehicle will be the next step.

Using a circuit tester like # PTW2993 test the output signals on your 2016 Ford Escapes 4-way plug. If you are getting an intermediate or no signal with the running lights on, then most likely there could be a loose wire connection or the converter in the harness may be bad.

The Curt T-One Connector # C56335 is the correct wiring harness to fit the 2016 Ford Escape.

expert reply by: Jared P