Trailer Turn Signals/Brake Lights Not Working on Trailer Towed by 2004 Nissan Titan

Question:

i had no running trailer lights, i replaced a fuse and now i have the running lights working but no turn signal or brake lights. i have the factory installed towing package. is there any way to check to see if the relays are good or is there a in line relay some where in the wiring? groung is good and trailer lights work with another vehicle. thanks for the help!!!

asked by: Jim D

Expert Reply:

This does sound like a bad or missing relay. You can test the 7-Way connector without the trailer attached to see if you get any signal at all on the turn signal/brake light circuit. If you do get a signal but the lights are not working on the trailer, it could be that the extra load from the trailer lights is not allowing them to function properly. No signal would indicate a problem further up, most likely a blown fuse or relay.

The 2004 Nissan Titan should only need 2 relays out of the 3 that come with the Factory Style 7-Way and 4-Way Flat Vehicle End Trailer Connector, # N40975. You will want to consult your vehicle owners manual to determine where are of the fuses and relays are for the towing package on the truck. If you need additional relays, you can use # C57000. The small blue relays activate the turn signal functions.

expert reply by: Michael H