Poll: Did you have an OEM Xenon bulb/ballast failure only on one side? Which side?
I was replacing my headlight lenses tonight, because I took them out to refinish them. I stood back to look at my work, and I noticed that the passenger side Xenon was dimmer and more yellow. So, I thought it must be a bulb issue. This was not a big problem for me, because I had bought a complete set of Xenons from a guy who works in a body shop ($80!!). The M3 they came off of had hit a telephone pole dead center, so the headlights and lenses were perfect, except the headlight assembly mounting tabs were all broken off. So, I decided I would just use those bulbs, since they were from a newer model. When I took off my old bulbs, I noticed that they were a mismatch. The drivers side were obviously original, and the passenger side was a newer replacement. So, I took the bulbs out of my spare assemblies, and strangely enough, it was in the same condition. Drivers side was apparently original, and the passenger side was a replacement. What are the odds of that? So, I put in the 2 bulbs that appeared to be Originals, and I saw the same issue. The passenger side was still dimmer and yellow. So, I put in both bulbs that appeared to be a replacement bulb. Same issue. I tried all of the various combinations, and switched bulbs left to right, and the issue was the same. BTW - these were all Phillips/Osram bulbs, 35w. This led me to believe it was a ballast issue. I went to remove the passenger side ballast from the spare set, and I noticed that it had been removed at some point. I removed the drivers side, and sure enough, the passenger side ballast was newer/replacement. I replaced the one in my car with the newer ballast from the spare set, and it solved the issue. So, it was a bad ballast.
But that made me wonder, what are the odds that I would buy a random set of headlights for parts, and they seem to have experienced the same bad ballast and/or bulb on the exact same side? Maybe it was just a strange coincidence, but I thought I would ask. Did you have problems with your factory Xenons on one particular side only, and if so, which side? This is not some sort of big revelation for all of us, but I thought it would be interesting to ask what others have experienced. BTW - I did search the forum for this, but I did not find anything.