Troubleshooting Right Turn Signal Not Working on Trailer

Question:

When I hook up my boat trailer to my F150 with factory towing package the right turn signal does not work. Looks like all the other lights work. I have only had the truck a short period of time so I’m not sure what happened to cause this. Is there a fuse or relay that could be the reason. Can’t find a wiring diagram for this truck. Thanks

asked by: Jerry B

Helpful Expert Reply:

The first thing to do is determine if the issue is on your F-150 or your boat trailer. To figure this out you just need a tester like part # PTW2992 and use it to test the right turn/stop pin on your F-150 connector. I've attached photos of the pinout for both 4-Way and 7-Way connectors for you to reference.

If the issue is on your vehicle side then you'll need to reference your owner's manual fuse section to see which one is related to the right turn/stop signal for trailer towing. If you can give me the year of your F-150 I can look it up too but I would just be referencing the online manual that Ford has on their site which is available for public view.

If the tester shows power on your F-150 connector then the issue is on your trailer and you need to check wiring connectors, grounds, and the wiring itself for that right turn/stop circuit.

Attached is a link to a helpful article we have for troubleshooting trailer wiring that you might also find helpful.

expert reply by: Jon G