I have an early 2005 645Ci. I apologize for the length of this but there's a lot going on. I recently cured an AHL issue by replacing the AHL module behind the glove box (thanks HerbP) The right (passenger) side headlight had been flickering prior to this repair and I had hopes this repair would fix both problems. It didn't. So currently the right side low beam flickers intermittently and occasionally flashes like a camera flash. I ran the diagnostics (ISTA-D) with nothing showing up. Lights activate when they should and they move around as commanded. Also the headlights don't seem as bright as I think they used to be. Xenon bulbs are a little too expensive to just start replacing and I'm a little confused about the "ballast" and "igniter" comments I've seen through my searches of the forum. So I'm looking for some guidance. Everything on this car is stock and I've confirmed moisture and corrosion are not issues here.
I thought I'd mention I found while running the diags. Under normal driving my low beams and high beams come from the same bulbs. The xenon shutter changes to switch from low to high beam. If I pull back on the beam changer lever to "flash" the lights at someone, the other set if bulbs light up. When running the diag software testing the high beams, it lights up the same set of bulbs as the "flash" bulbs. So that also has me scratching my head.