Right, I know that is what you were saying. You also said the D1S came with a ballast and the controls for the lamp leveling were integrated into the ballast which had me confused since as you now mentioned there are additional controls in the headlamp assembly. AS I understand automotive HID lighting, there are ballasts and there are igniters so perhaps it is the igniter that is included with the D1S.


UPDATE: After a bit of research, as I suspected, the base is NOT a ballast but the igniter for the lamp.

 

I have a 2005 XJ8L and the driver side headlamp just became a violet color. After reading these posts I have determined I have HID Xenon (projector look "eyeball" when looking from the front) my question is how do I know if I just replace the bulb or if I also need a ballast? I also read that I should replace both sides.... True? By the way, the headlamps do not go up and down when the car is first started as I have read they are supposed to do?

 

You can just replace the D1S bulb assy and/or just the ballast. The problems arrises when you purchase a used ballast, there is no warranty and it might last just a few minutes or a few years.

Note: The base on the D1S is the ignitor.

 

Hello all. I just went through the HID flickering until one light finally quit completely. I bought two new D1S bulbs from Amazon and it helped one side a bit, but the side that was out was still out. Checked pricing for used ballasts and found new Valeo LAD5G 12 pin ballasts on line at HID Kits and HID Lights - HID Origin for about the same price. The cost is 135 UK pounds each for brand new ballasts plus shipping which was quite reasonable. They just arrived and I quickly installed new ballasts and bulbs and connected everything up. Both lights are shining brightly and steady with no flickering. These ballasts were exactly the same manufacturer and model as old ones and plug right in with new torx screws included. I am much relieved and now just have to warm up garage so I can install bumper cover tomorrow. Hope this helps. You just have to be careful about the number of pins on the ballast as the early 205 XJR's (like mine) use the 12 pin ballast while later ones us a 4 pin. If in doubt you have to take light assembly out to check.
Hope this is of assistance. Thanks.