Only Tail Lights on One Side of Trailer Work when Connected to a 2005 Nissan Frontier 7-Way

Updated 06/27/2012 | Published 06/24/2012

Question:

yes, my dad hooked tow lights to the 7 pin on frontier. the only thing that works are taillights on one side. none of the other lights work. when he plugged it in he heard a pop noise. there are no blown fuses. he figured the trailer was wired wrong or something. wish i coul just splice into my tail lights.

asked by: Jeff F

Expert Reply:

The pop you heard could have been a relay that tripped related to the trailer wiring. Use the owners manual to find the locations of the relays related to the trailer wiring. I have also included a picture that shows a standard 7-Way configuration on a vehicle and on a trailer. You can check the wiring on the trailer to see if something is wired incorrectly.

There could also be a bad ground. Make sure the trailer and vehicle side connectors are free of dirt and corrosion. Make sure the main ground on the trailer side is attached to a clean and corrosion free bare metal surface and then do the same for the trailer lights.

You can also check for any bare wire that is touching the metal trailer frame as that could cause a short.

expert reply by: Michael H