doesn't matter if it is a 4 pin or not, you still wont have tail lights untill the relays are installed. I found this out the hard way. After installing the $15 4 pin wiring harness with my aftermarket hitch the only lights that work are the blinkers and brake lights. Then the nissan harness, available only in 7 pin, was bought and a 7 to 4 adapter was purchased at checker or someplace. Then and only then did the tail lights work. Sorry if I was unclear earlier.