I have been having a persistent problem with the driver side headlight beam going out. I replaced the bulb and it went out after a week. I put a new bulb in, it lit up, but went out the next day. The bulb is good (it lights up off the battery). Now, when I install a good bulb it doesn't light up. I'm using Heliolite Xenon H11 halogen bulbs. The other low beam, both high beams, and both parking lights are fine.