Here's what I've found over the years.
It's directly related to the auto-headlight feature trying to ignite the HID's while you're turning the truck over. Basically the fact that the truck is drawing so much to turn the engine over, very little is left for the HID's and it starves the ballasts. That's a sure fire way of KILLING an HID ballast over time.
2 fixes:
1. Disable AHL. There's a how-to on that IIRC. But that way YOU control when the HID's ignite, meaning the truck will be running, and you won't starve the fuckers when you go to start the truck.
2. (And this one I use) park the truck with the parking brake. Even if you just push it down enough for the truck to realize the P-Brake is on. When you start the truck the headlights won't come on. Just pop the P-Brake off once you're set to go and your HID's will have full power for ignition.
My 05 Blazer I had back when I was a teenager had HID's, and the pass side never ignited one winter when my P-Brake had seized and I couldn't use it. (was a 5spd as well... so that was fun.
) Not long after the pass side went out. I put DDM's in the Sierra the first time around and I noticed that happening too. Basically I've used my parking brake on this truck since day 1 of me owning it. I've only ever replaced my DDM ballasts due to failure (road salt got to the contacts on the ballasts). Last set I changed is because I upgraded to Morimoto 3Five ballasts, instead of generic stuff.
It's usually ALWAYS The passenger side that acts up. Why? I dunno. My theory is it having something to do with being further away from the power source, resistances in the harness due to length of wire, etc. etc.
So try the parking brake trick first before that ballast goes kafuckingboom and see if it helps.
