Running Lights on Trailer are Not Working or On All the Time Using Adapter # 37385

Question:

signal lights work, i have no running lights until i move the brown lug to a different location but then the running lights stay on allthe time. I have a 2010 Frontier.

asked by: Lynn M

Expert Reply:

I recommend testing the 7-Way trailer connector without the adapter plugged in using a circuit tester like # 3808 if needed. You can use the included picture to determine what the functions should be. It is possible that something does not match up between the 7-Way and the adpater. If the 7-Way is functioning properly, plug in the adapter and test again using the 4-Way picture included. If the signals coming out the 4-Way side do not match up, you may need to re-pin the adapter.

Also make sure that your trailer side connector matches the functions of the adapter.

This could also indicate a ground problem. Check the main ground on the trailer side. It should be connected to a clean metal surface on the trailer frame. Look for nicks in the wire that may be touching bare metal. Check the grounds at the trailer lights as well. They should also be connected to bare metal surfaces. A bad ground can cause all sorts of issues.

You will also want to make sure that any and all fuses and relays related to the trailer wiring are present and functioning.

expert reply by: Michael H