Litronic occasionally turns itself off?

[fridsten]

I have factory Litronic headlights on my base -99. Recently I've discovered that the left light turns itself off from time to time. There's no obvious pattern to it. When I turn the lights off and on again, it works again. The difficult thing is to know when it goes dark.

I'm guessing it's either the Control Unit or the Ignition Control Unit for the headlight. Since it only occurs on the left headlight, I don't think it's related to the switch.

In Sweden it's mandatory to have low beams (or DRL) turned on during the day as well, so I need it to work.

Any thoughts?

Forgot to mention that I've replaced the bulb. That's not the problem.

[JFP in PA]

Ignitor.....

[fridsten]

Thanks!
It seems I can buy a new one for either around €600 or €40 depending on whether I go for original Porsche or VW/Audi...

[Marc_986]

Just how did you the check the bulb? Swapped left to right or replaced with a brand new one?

I had similar behavior in my previous 3-series. The intermittent turn-off was sometimes triggered by a bump and happened more often in winter. I swapped bulbs left to right, checked all the wiring, electronics for loose contacts and solder joints etc.

Drove me mad until I started replacing parts. Bulbs being the cheapest I did them first. Presto, no more issues. In my experience Xenon bulbs last about 6 years. By that time they loose too much light output or start giving problems.

[Burg Boxster]

yes, swap bulbs left to right is first test. if issue follow then bulb is most likely issue.

if not, then issue upstream from bulb...

If bulb bad, replace pair... unless of course you selected that secret special Porsche option M-BulbSelect allowing you to choose which bulb to run when ;-)

[Smallblock454]

Mine had the same problem. Did only occur on the left side for long time. Got worse. Both headlamps turned offv while driving. Was the light switch.

[fridsten]

Thanks, everyone! I replaced the bulb with a brand new one. It's only on the left hand side and only occasionally, but according to Smallblock454 it could also be the light switch? I've bought a new ignitor and will replace it after the winter. The car's currently under a blanket since summer is over here in Sweden.

[fridsten]

I didn't replace the ignitor, but I did mount a new switch. That didn't help, though, so the ignitor is next on the list.

[fridsten]

So I've replaced the bulb, the switch and the ignitor. Still the problem persists. Does anyone know where else to look?

[fridsten]

A new ballast solved the problem. However, since I wasn't too keen on paying the Porsche tax, I found a replacement on Amazon. The difference was that it didn't have the screw holes for mounting it to the headlight casing. But for a fraction of the price (I'm talking 1/20th!!!) it was worth a chance. It turned out to not only work, but I could also swap the electronics into the old casing with the screw holes. That's a win!

[theiceman]

Originally Posted by fridsten

A new ballast solved the problem. However, since I wasn't too keen on paying the Porsche tax, I found a replacement on Amazon. The difference was that it didn't have the screw holes for mounting it to the headlight casing. But for a fraction of the price (I'm talking 1/20th!!!) it was worth a chance. It turned out to not only work, but I could also swap the electronics into the old casing with the screw holes. That's a win!

posting a link to amazon may help future enthusiasts..

Great you got it working.

[fridsten]

Originally Posted by theiceman

posting a link to amazon may help future enthusiasts..

Great you got it working.

I'm in Sweden, and unfortunately I can't find the same product on amazon.com. However, all I did was search for the Porsche part no. 99363119302.
Here's one that looks like it's exactly the same:
https://www.amazon.com/MOTOALL-Headlight-1307329052-1307329023-Mercedes/dp/B0B7NCZP9Z