1997 Harley Roadking Headlight And Passing Lamp Wiring needed to cut the wire harness behind the headlight and pull through the grommet. of course i was in a hurry and did not mark them. here is a wiring diagram for your bikes head light area. Installing the Harley Davidson Fog Lamp KIt on my HD Ultra Classic and I ran into a snag while. Harley Davidson Headlight Wiring Diagram ~ hello friends our Aftermarket headlight wiring? | Harley Davidson V-Rod Forum Not quite. The 2003 Wiring Harness does not have a headlight "plug" on it. The wires run from the harness all the way to the light sockets. Regardless of what you decide to do, you're going to need to do some modification to the wiring harness to refit a headlight to a 2003. Yellow is positive power for the Low Beam.