From your post in the other section....
I just hooked my headlight up yesterday on my 99. There is a set of wires (all together, not individual wires) that comes from the killswitch /headlight controls. Under the hood that wire splits into two directions, one direction heads down towards the motor for the killswitch. There should be two other wires that come out of the set that are seperate from the wires heading to the motor. Those are for the headlight, green and yellow. I reached in and grabbed a black wire out of a set of 3 other unconnected wires to ground the black wire coming out of the headlight. Not sure what set of wires I took the ground from, but it worked. I had two green wires coming from the headlight, but one had a small bit of blue stripe also. I used the solid green wire, which left I think 2 other wires leftover for the oil light. Can't really help on the key switch.
It doesn't get much more straightforward than that. It's easy, follow the wires coming from the headlight switch, when you find the two wires, connect them to your headlight. Done. Or, does the switch not even have wires connected to it yet?