On my '95, the green wire goes from the solenoid and into the headlight housing, into a plug with two other wires, that are red, I believe. I'm guessing, but I think it's probably the wire that sends juice from the starter switch on the handlebars to the solenoid. The starter relay on my bike is also in the headlamp housing. One of the mechanics at the local Harley dealer suggested I check this green wire, after I had replaced all the other cables, solenoid, and relay, and was still having the intermittent starter problem. It's been a couple of months since I replaced the green wire, and so far so good.

 

Yes that green wire to the starter solenoid comes from the start relay