Had the dealer install the tow kit on the Dak and I'm not sure if I've ever had power to the box for
the trailer running lights. Has anyone else had this problem or does anyone have the instructions/
diagram for the trailer harness?

Thanks

Use a test light and wire And check your plug at the truck and see if you have power to the pins. They are color coded and the truck wiring should have a plug for trailer tow assessory plug to plug into.. My 97 Dakota does. Trailer wiring is not that hard. It is all color coded. The yellow,green and brown are the trailer lighting wires. white being the ground. Make sure that you have a good ground to the trailer and truck. Don't rely on the hitch to provide the ground. Once you have the trailer hooked to the truck and the lights plugged in hook a good jumper wire from a clean spot on the trailer hitch to a good clean grounding spot on the truck and see what you have. Grounds are very important.

It's a 7 pin box (not a 4) and everything works except the running lights. There is power to the
harness relay and the relay tests good. Ground is good.

thanks

Tail and side markers should still work of the same wire Brown. I know that my 2001 enclosed does.
http://www.accessconnect.com/trailer_wiring_diagram.htm

Found it. After taking the spare tire out and tracing wires I see 2 wires (red, blue) going towards the front, must be to the battery. Follow the wires and I see them laying on the exhaust. Good thing I had this installed at the dealer!

Thanks for the help Don.