Troubleshooting No Power at Turn Signal Pins After Installing Curt 4-Way to 5-Way Adapter

Question:

I have a flat 4 pin on the car but when I plug the 4 to 5 pin adapter in only the running lights are hot. The turn signal yellow and green pens and the blue back up pin are cold? I have two different adapters and the results are the same. This is a 4 to 5 pin connection for a boat trailer with surge brakes. I have the adapter from etrailer.

asked by: Jerry J

Expert Reply:

The Curt Trailer Connector Adapter # C57187 that you referenced will simply plug into an existing 4-Way connector on the vehicle. The additional blue wire from the adapter will need to be spliced into the reverse circuit wire on the vehicle for that pin to be active when reversing.

If you aren't getting any power at the right turn and left turn signal pins with those functions activated on the vehicle, I recommend inspecting the vehicle's 4-Way connector. Check for any debris or corrosion that might be built up inside or around the pins that are preventing a good connection with the adapter. Since the same issue is happening with two different adapters, the problem seems to be with the vehicle's connector or wiring. You can test the 4-Way before attaching the adapter with a circuit tester like # PTW2993 to make sure it is getting power to the turn signal pins.

If you are still unable to resolve the issue please let me know and we can continue to troubleshoot.

expert reply by: Chris R