On my 08 FatBoy, I just put a HID headlamp in it and since then when it gets wet(once washing and once rain) the low beam light won't come on. Last night it happened again and I worked the hi/lo switch about a dozen times with the key off and it started working fine again. I am gonna go into the headlamp bucket for a look see but I am thinking the HID lamp pushed the switch over the edge. It pulls 6.4 A on startup.

On another note, I put the passing lamps on a relay and are wired on a different circuit, so the overall load on the switch is less then it was before.

I guess what I am asking, how do the headlight switches act when they are going out?

BTW, my garage door opener quit on me the same time as the low beam acting up, so that reinforces my thoughts it might be the switch.

Does the headlight switch respond to being cleaned and lubed with WD40/contact cleaner? Is this even possible?

Bike has 12,500 miles on it, and I do have the extended warranty on it, but I dont know if they will cover it with the HID headlamp in there. I suppose I could pull the HID out and put the stock bulb in there if I have to.

 

From the factory, the full voltage of the headlight is passed through the switch. You are on the right track with your accessory lights being run from a relay. That helps tremendously, but you did not mention how the wiring for your aftermarket HID headlamp is ran. Hopefully you have the wiring ran through the switch and then to a relay as a 12 volt turn on source. The main power for the ballast should be run from the battery to your relay so as to avoid burning out the tiny handlebar switch.