Troubleshooting Parking Lights Not Working on Trailer

Question:

Lights all work but parking lights is it a relay or could it be back wire

asked by: Tom

Expert Reply:

Since everything works except for your parking lights, the issue is either with a ground wire or with that specific wire function. Often when one function isn't working, it is due to a bad ground connection, so I recommend checking that first. You will want to make sure that your ground wire has a bare metal to metal connection that is free of corrosion or debris.

If that doesn't solve your issue then I recommend checking your running light pole at your trailer connector. If you have a 4-way, this is the brown wire. In a 7-way this is also the brown wire most of the time and is located at the 3 o'clock position. Use a circuit tester like # PTW2993 to test this. If you don't have function there, check your owners manual for fuse locations and possible relay locations.

If you have function there, then connect your trailer and test on the other side of the connection. If this doesn't work, clean your connection or replace your connector on the trailer side.

If it does work there, then trace your wire to see where the tester stops functioning. You have then isolated the short and will need to replace that section of wire. I've attached an article to assist.

expert reply by: Jason S