Troubleshooting Turn Signal Function On Two Separate Trailers

Question:

I am pulling my hair out. I have boat and a small flat bed trailer and the curb side blinker does not work on either one. Replaced the one bulb that was burned out and have connected both trailers to two different vehicles with and without the a seven way connector to the 4 way. The trailers have different makes of lights and the vehicles have different connectors, bulbs are good and so are the grounds. Curb side blinkers just dont like me!

asked by: Paul L

Expert Reply:

It sounds like you have a bad ground in your vehicle. Since connecting the trailers to other vehicles allows them to work properly, the issue must be in your vehicle. For many functions to work, and just one to not work, usually that is a ground issue. Check your connection within your vehicle for your wiring harness and ensure you have a clean ground connection that is bare metal to metal. You may need to create a new ground to solve the issue. Use a circuit tester like # PTW2993 to confirm signal function.

It is rare to have the same issue with both trailers, but the lights are often grounded through the hardware and you may want to make sure the hardware on that curb side blinker is connected properly. Using other vehicles can allow different power to flow and may not show an issue even when there is one if there is enough power running through to compensate for a faulty ground that is still somewhat functional.

Let me know if you need to continue to troubleshoot.

expert reply by: Jason S