jmp470

Jason,
I have a CPO and it is still covered under a warranty, but I have to pay a co-pay for the work. Anyways, I tried to do the bulb myself and got it out and put back together. Just to find out that the dealer changed out the ballast. In the end, in my case I should have just let them do the job.

In your case you would have to either take out both bulbs to see if that works or you would have to change the ballast. Hope this helps

Jason Teller

My car is CPO as well so maybe I'll just let the dealer deal with it after all.

timba

I am having intermittent headlight trouble on my passenger side as well on my 2004 A8L. I have replaced the bulb, swapped the ignitor side to side, and still have no luck. Does anyone have any suggestions as to what else to check? I see from Bentley's wiring diagrams there may be a relay behind the instrument panel, does anyone have a hint as to how to access this relay? I am at a loss as to where to look next.

Thanks, Tim

timba

The "box" you are talking about is called the ignitor. High voltage, y'all be careful. Audi recommends you disconnect the battery and discharge the ignitor by selecting the lights on for several seconds before messing with it. The problems you had re-installing the ignitor were because there is an alignment ring inside the box and if you place the electrical connector in place before installing the "box" the ring can twist. The ring can also fail to align properly following disassembly. Slide the ring back into position and it should all fit together smoothly. There are THREE slots for those tiny "nubs" to align with to hold the bulb in its proper position and prevent it from rotating, vibration control, I believe.

These cars are somewhat over engineered

Tim 2004 A8L

aceecaus

I had this same issue on my 08. Headlight would turn on, stay on, go off. Warning light come on in the instrument panel. I'd cycle the lights on/off and the light would come on and stay on until I turned on the brights, etc. Weird.

Turned out, there were some codes stored in the DTC and once they were cleared out, I haven't experienced the issue again. Apparently, before I bought the car, someone had let the battery die down and this caused some codes to throw and this caused all of the headlamp issues.

All's good now.

AudiOx

Great tip about the ignitor voltage.
Those little nubs weren't on the OEM bulbs, just the aftermarket ones so it's not an Audi engineering feature. They seemed to not allow the ignitor to move in that last .01" so the 3 tabs could engage.
I also noticed the OEM bulbs had more support in the form of a metal 'tripod' that decreased much of the cantilever on the bulb. The aftermarket ones were just supported at the base of the bulb. For $14, if they last a year, it's worth the money.

Jason Teller

Went in to dealer today and they tested everything and determined that the bulbs were on their last legs. This is their explanation for why lights were working only sometimes. I'm not sure I buy it, but it was covered under CPO warranty, so no harm no foul. I'll give it a twirl for now and cross my fingers.

Mike_k

Most likely the bulb is your issue. When the ballast first receives power it will put out maximum voltage and if the bulb doesn't fire it will cut power. The easiest way to determine if the bulb is your issue is to turn the headlights off and then back on. If that bulb then comes on then most likely your issue is the bulb.

Audiq45

I have a 2004 Audi a8l and I'm wondering if anyone knows how to install the drivers side ballast and HID bulbs

Audiq45

I was wondering if anyone knows how to change the ballast and HID bulb on the drivers side of a 2004 Audi a8l