My 2004 XK8 is having a drivers side head light issue. I got a new bulb, checked to make sure it is good by switching it to the passenger sdie. It works. Re inserted it to the drivers side and it dosen't work. Checked all the fuses and re lays and they are fine. Only other related problem was moisture in the head light area. The head light seemed to go out around the same time. I blew the moisture out of the head light area. This has the high beam bulb and the day light bulb in it. Didn't seem to see any moisture in the actual head light or dip light as it is called in the manual. Any ideas? Thank you. Mike

 

Do you have HID bulbs or halogens? The HIDs have a big, square metallic box attached to the bulbs.

If you have HIDs, then I would guess that the ballast has gone bad. Some people mistakenly believe that the big metal box on the back of the bulb is the ballast. That is incorrect. The big metal box is the igniter. The ballast is mounted separately from the bulb. On some HID setups (not XK8s) the igniter is a part of the ballast, on others, like XK8's, the igniter is attached to the bulb.

 

HID's..........where is the balast located?