Troubleshooting Running Light Circuit of Trailer Wiring Not Working Afater Install

Question:

I installed following instructions. Stop and Turn signals work fine but no Tail lights on trailer. Car lights work fine. I checked the 4 pole connector on the car. No tail lights there. Please help - Thank you

asked by: Didier C

Expert Reply:

Sometimes the issue you are having is simply just the connectors not fitting tight enough for the connection to be made. Unplugging and reconnecting the setup sometimes fixes this. After you try that use a circuit tester to test the brown wire coming from the connector on the left side when the running lights are on. If there's voltage there but nothing after the converter box the box is bad. If there is no voltage there then the issue is the connectors still aren't connecting with the running light circuit of the vehicle.

I attached a couple help articles on trailer wiring troubleshooting for you to check out as well.

expert reply by: Jameson C