xenon headlight - find moisture

[dave08]

Hello!
Short story: SID alert to a xenon headlight  failure, bulb and ballast tested, finally the control unit that seats under the headlight itself. This was the problem as the connector was full of moisture. The unit itself seemed ok, but he gave it a clean with compressed air and after the assemble it worked right away. Today it also worked even through an immense fog for about 18km.

The left headlight (LHD car) itself has a very little moisture in the left corner, but this must be recent, In more than 16 years I've never noticed it before. About a month ago I had to remove the side rubber strip on both headlights as there were bits missing and quit rotten, and replaced them with a window rubber seal. It is unnoticed until 2 or 3 meters away...It didn't seem that water could enter from the side, where the new rubber was fit, but more tests were needed to be sure. We guess the problem might occur again in the future, so my question is: What is the best way to find where the moisture comes from?
The bulb rubber seals are ok. I checked the prices for a new xenon headlight and it's scary!
Thanks and regards!
Dave

[sgould]

I don’t think that the headlamps are supposed to be sealed tight.  At least, on the 9-5 there is a 6 inch rubber tube dangling beneath each headlamp.  It’s for ventilation.  The workshop manual is clear that this tube must be left unobstructed, and not bent or trapped, when fitting the headlamp, or parts nearby.  If it’s sealed or blocked, the headlamp will mist up.

[dave08]

Thanks for the reply.
I didn't see a tube hanging there for ventilation on my 9-3...Maybe Xenon requires a complete sealed headlight, I don't know
I'll be following this closely.
Regards.

[sgould]

There's this longer tube on the underside of the 9-5 and is there a short vent on the 9-3 in the second photo?

Both are Xenons.

[smurkenstein]

Think I have some bi-xenon housings in the garage - I can have  a look later. I did some HID swaps a while back and I don't remember the bulbs fitting particularly tightly.

[dave08]

There's this longer tube on the underside of the 9-5 and is there a short vent on the 9-3 in the second photo?

Both are Xenons.

The mechanic didn't mention those...I'll be alert next time as I'm almost sure it will happen again.
Thank you so much! I'll be posting any interesting updates.
Thanks.

[dave08]

Think I have some bi-xenon housings in the garage - I can have  a look later. I did some HID swaps a while back and I don't remember the bulbs fitting particularly tightly.

thanks for the reply.
I'm hoping to find the moisture ingress. But, If I need the housing itself, I'll keep this in mind.
Thanks!

[smurkenstein]

hi Dave, sorry. I had a look today and I couldn't find them to take some photos. I think when my aero went to the great parts department in the sky I left the lights in the boot. I had tried selling them but they were from France and LHD (understandably, nobody wanted them).

[dave08]

hi Dave, sorry. I had a look today and I couldn't find them to take some photos. I think when my aero went to the great parts department in the sky I left the lights in the boot. I had tried selling them but they were from France and LHD (understandably, nobody wanted them).

Thanks, no problem. LHD, exactly what I might need one day   Anyway, so far everything is ok. Heavy rain expected tomorrow, so I'll be checking it.

[dave08]

so far everything is fine. Even after the lately morning frosts and after 55km under heavy rain today, no moisture found and the headlight is running fine.
I wonder if replacing the rotten headlight rubber strips had anything to do with this happening 2 weeks later. I used regular window rubber sealer...
I'll post if I find anything new.
Regards and merry Christmas!