Troublehsooting Trailer Lights Not Working With 2012 Nissan Frontier

Question:

Several years ago I sucessfully installed your Trailer Update kit with the 7 pole connector and all the relays. This year the lights stopped working. The terminals to the back of the 7 pole connector were corroded. I puchased a reaplcement harness and 7 pole connector but it still does not work. I checked the fuses and they appear to be ok. What else can I check?

asked by: Marty Z

Expert Reply:

I imagine it's a ground issue, but there are a few troubleshooting steps to check. You'll need to use a circuit tester such as # PTW2993 to test the 7-way on your Frontier after disconnecting it from your trailer. Check the wiring going into your harness from your taillights to see if those wires are carrying the correct signals, if not then the issue is with the vehicle wiring. If the signals going to your harness are okay, you'll need to test the signals coming out of the harness, and if they are correct then your issue is likely going to be with the trailer side wiring.

Also take a close look at your the ground connections, as they can be the cause of numerous lighting problems. You'll want to make sure your grounds are securely attached to bare metal surfaces free of any paint, dirt or corrosion of any kind. Also check your wiring thoroughly to ensure there are none that are crimped, broken or otherwise damaged. I've added links to a pair of help articles on trailer wiring that you may also find useful.

expert reply by: Kyle S