One of my low beam HID bulbs is blinking on and off, mostly off. I checked Rock Auto for replacements, and saw no listing for ballasts. Do bulbs come with them built in? In looking through the forum I see suggestions about the ballasts being mounted below the lamp bucket, but no guidance about how to test or find replacements. This is my first car with HID headlights, so I've not stumbled into these specific weeds before.

 

If you look at the picture below, the ballast is the silver square you can see:


It basically is an electronic module for the headlights, so no bulbs involved.

As you can see, it is screwed to the bottom of the headlight unit, so you need to remove the headlight to be able to access it.

Best regards,

Thomas

 

Depending on which side the blinking is coming from, it could be a relatively inexpensive fix... or not. From memory, I had a bad ballast on my '04 that I had to deal with right away when I picked up the car, five years ago. IIRC, the right-hand ballast is different than the right has leveling sensor bits inside and doesn't have an aftermarket equivalent. The left-hand one on mine was dead, and I replaced it with an inexpensive (sub-$60) aftermarket ballast off Amazon. No problems in the past 5 years/100k miles.

Paul
'04 XJ8, 240k miles

 

Thanks Thomas and Paul. Photo really helps. Last night the light worked as usual. Must be a failing connection somewhere, I hope to be able to find it just to prove the fault. I was thinking by 08 the self leveling lights were gone, so ballasts are the same? Could this problem occur with a bad ground? The famous ground studs are in there somewhere, right?

 

Had the same issue on my 06 str. Same headlights. Finally found loose connection at plug going to ignitor. It fell out when i was going to change the bulb. I had already changed ballast. Used one drop of glue. Never happened again

 

No, the gorund studs are behind the headlights. I circled them in Red in the following picture:


Here's anothe picture with the headlight in place:



Best regards,

Thomas

 

Early models have Valeo Lad5G ballast 12 pin for the xenon headlights with selfleveling connectect to one of the rear height sensors .
once you put in new ballast the self leveling is not supported anymore. You would have to switch to Hid over Sdd . The self leveling of the headlights is not needed (since on later models with just 3 height sensor there is none installed in the headlight box)
later Models have Valeo Lad5GL ballast 4 pin.

The ground studs could be another reason for flickering. Those are the 3 mass connection below the engine bay upper front cover . You will reach 2 of the just like that, the 3th on is hidden a bit lower all behind headlight box . Undue carefully tend to break of. If so drill hoses and put in aluminum bolts from behind the frame , do not drill too deep into fuse box . I did it just by removing bumper and headlights.
another reason is sometimes the stalk at the steering wheel that has got to be exchanged




Also the ones with chrome rings (from xf)would fit
I installed those on my 2003 xj6