DIY: Removing headlight and replacing HID ballast

Stimpy · March 11, 2016

My symptom: My right headlight was turning off by itself, but when I turned off and on the headlights, it would come back on.

Diagnosis: Bad HID Ballast. The ballast in an HID light is the same concept as a ballast in a garage florescent light fixture, so it’s not a difficult DIY repair.

I have read that dealers will not do anything to repair a headlight, only replace it, if there is anything more wrong with the headlight than a bulb out. They will charge $7000 for the part, and probably a $1000 for labor.

You can do it yourself for a lot less. The usual discount Lambo vendors will sell you the ballast for around $500. The part is common a VW/Audi part, and it’s know to fail frequently, so you can find the same part number for around $250 from non-Lambo sources. Since I am doing my own labor, I decided to try a $20 ballast that claims to be the exact same product with a different label. So far so good, and so cheap, I bought a spare.

http://www.amazon.com/gp/product/B00WGVLUQ...ailpage_o00_s00

I just noticed this ballast doubled in price on Amazon, so you may not get the $20 price. You can use camelcamelcamel.com to alert you if it drops again.

From what I could see, you do have to pull the headlight to replace the ballast, which is not that much fun, but it’s not that hard, and you shouldn’t worry about breaking the headlight as it’s a pretty sturdy assembly with very thick glass.

To remove the headlight, you need to jack up the car and remove the front wheel. When jacking the car, always use a jack on each side, and go up only an inch or 2 on each side at a time until you have the front wheels off the ground. That way you don't twist the frame too much.

Next you need to remove 2 sections of the plastic wheel well liner to get the light out, and they are bit fiddly.

To get the fender liners out, start by removing all of the Phillips screws and all of the 10 millimeter bolts from both liner sections. You do not need to disturb that the back portion of the fender liner.

To get the big top section out, push the wheel well liner toward the center of the car, and down from the inside edge and rotated a bit forward until the liner unhooks from being wedged in the fender lip. Pay attention to the wires and hoses near the top of the front suspension arm to make sure you don’t pinch them.

Remove both fender liner pieces from the car completely to make it easier to work on the bolts for the headlight.

Good news, removing the fender liners is harder than getting them back in.

Next, you are going to remove the headlight, which happens to be much easier getting out than going back in.

To remove the headlight, first, undo all of the connectors for the various light bulbs. Every connector is different on how you unhook them, which is a funny thing with cars, but they all come out.

The headlight is held in kit-car style with 3 brackets: One very obvious on the back of the light, one not so obvious on the side of the headlight, and one in the front. If you took out both the liner pieces, you won’t have too much trouble reaching them.

On the side and front, I ended up removing the nuts holding on both headlight to the brackets and the brackets to the frame.

Once you get all 3 sides free, the headlight slides out down and backwards and out the fender.

To replace the ballast is just a couple of Allen key bolts, and you pop the new one in place. The connector at the bulb just turns counterclockwise to twist off. Easy.

Then to put everything back in, you may find a helper is needed to hold the headlight up and to help you align the headlight before you tighten everything back down. Side note: If you have ever changed a headlight on a modern Range Rover, you will curse Lambo for the makeshift mounting of these headlight. On a Rover, it pops in, aligns itself, and then you push down on a couple of tabs to secure, and you’re done.

I used a bunch of shop towels to hold up the headlight while I did the brackets (when you have reluctant-to-help family members, you learn to use towels, tie wraps, and masking tape to be a second set of hands).

Once the brackets are attached, you can snug the nuts just enough so that you can still move the headlight to align it in all dimensions and the headlight will stay in that position before you tighten down the nuts all the way. Make sure you get the headlight perfectly aligned so you don't make your Lambo look like a kit car after the job.

I took the time to also remove the 2 ground wires on the frame, file down both the connector and the frame mounting points, and add some dielectric grease to make sure the ground points are good. Others have speculated that grounding issues cause headlight failures, but I didn't see any evidence of that with my car, but might as well clean up the grounds while I am in there.

The fender goes in like it came out, but you will find it much easier to get them in than out.

Done.

While I had the light out, I looked at what it would take to open the glass for polishing, and it's definitely not easy. You can't bake them off, and there is a built in lip on the glass all the way around that makes it so you can't just run a blade through it. So no conclusion on how to open it.