1999 A8 xenon headlight problem.
 

Hey, I got one for you guys. When driving with the headlights on ( low beam only ) both lights will dim slightly then about 10sec later the drivers side light will go out and will give me the light out warning. This happens only intermitently, mabey once or twice in a 1 hr period. If I just flick the light switch off then on they both fire right back up. I dont know much about xenon lights but I think it's safe to say the bulb isn't burnt or burning out if comes back on after reseting the switch. Could it be a balast issue? Any suggestions appreciated.
Thanx

Each xenon has an igniter(ballast) and a control module (not the leveling motor). If not one of those, bad connection.
Igniter inside housing...control module on outside back.

I believe your problem is on the ballast, i ever have similar problem like yours, finally i got help from http://www.oemxenonpart.com They gave very fast and excellent service and helped me out.