One of my D2S lamp flickers and sometimes does not turn. When I do rev the engine while flickering sometimes it helps stabilize the flickering and the bulb ignites properly. The other lamp works perfectly fine. I installed Hella ballasts and D2S bulbs [used]. Is it the bulb or the ballast? Any way to troubleshoot?

Check the wiring and make sure the ballasts have a good ground.

So does anyone else have anymore input on this? I've experienced a few problems like this also, mainly with cheaper non OEM HID kits though.

Get a wiring harness. It should help.

I have the wiring harness. Tonight I've noticed when I turn the lights on [driverside will not turn on], shut it off then on again and the driverside would come on, no revving no nothing. Now it won't turn on at all. Possibly a blown fuse. When the lamp was flickering it was a reddish color that was produced.

Anymore insight to a solution guys? I know I'm being vague, but all the wiring and plugs are all there and connected properly. I'm not too familiar about the specifics of which the xenon bulb operates. I know that there a small salt capsule filled with a xenon gas then when excited by an electrical charge from both end, produces the light we see. Wouldn't a faulty bulb just stop working?

Could you tell what type of noise is the ballast is making?

Under regular startup the ballast should create a humming sound. Which would then quiet down.

When my ballast fails to light the bulb it would make a few clicking noises then shuts down until reset.

I think a ballast would try to ignite even which a broken bulb.

Also check the gauge of the wire you are using and the ground point.

The vehicle in which I performed the HID upgrade to was an E300 with composite lamps. I know that other E-Class Benz's have the exact same wiring setup as what I did. Meaning that even if I replaced the headlamp assembly with one of xenon, I would still have the same ground points etc. It's odd because the other side is wired and installed in the same manner and has not a single problem. As of last night playing with it when I got back the driver side will not turn on. I will check if any fuse broke for that circuit. When I try to listen for the ballast it's somewhat difficult to hear due to the fact that I have to be in the car or somewhat away from the ballast while powering up. Last I listened the ballast, it does have a nice hum while they are initially warming up. Hopefully it's only the bulb that is defective...