Here's the rat's nest of wiring that came with an eBay dual 55W HID Bixenon kit (the other light is going into another bike). Even ignoring the second headlamp, this is a lot of unnecessary stuff.
The way I'm wiring it, I cut (& soldered) things down just to this:
(could have gone even shorter with the wires but I wanted to have plenty of room if I ever need to move the ballast and igniter for any reason)
- The top cable will trigger the HID capsule to move to the "high" position when hi-beam is selected.
- The red wire will connect to a power supply - in this case the blue wire I left out of the connector from the new switch.
- Black will attach to a suitable ground (earth) point.