2005 HID Hi Beams, and O-Ring problems

Yes, I know that HID headlights are an oft-discussed topic, but my particular experience still perplexes me.

I just got this car, and it failed inspection because the passenger headlight would not do brights. It was not clear to me, until today, how HID headlights go from low beam to high beam.

My passenger headlight was staying on as I flip to high beams, but its reflector was not moving- only the driver side. I went to the trouble of pulling out the bulb, (because I saw an Eric the Car Guy video where he had the same problem, and resolved it with a new bulb). Now that I understand how they work, I don't see a new bulb would have anything to do with the reflector not moving.

I got the bulb out using my frozen fingers, then tried flicking the lights from low to high, and to my surprise, the reflector moved! I put the bulb back in and the reflector still moved. All fixed. Maybe the bulb had been installed cockeyed and was impeding movement of the reflector. I don't understand what caused that passenger reflector to be stuck, but as long as it will pass inspection tomorrow, I'm happy. Heck, even if brights fail on one side, HIDs are bright enough, who need hi beams?

Oh- the other topic. The dang O-Ring on the big headlight cap seems to be too large. Try as I might, I can't get that cap on with the O-ring. So, for now, I pulled the O-ring off and put the cap on without it. I'll get through inspection and re-visit in warmer weather.

Maybe I should try boiling the O-ring, or wipe it with alcohol to shrink it. Or maybe I can buy a new one somewhere.