Recurring headlight condensation

[Conquistador]

Does anybody have any easy methods of removing condensation from the inside of a headlight lens? It only ever happens on the one side. I don't particularly want to go drilling tiny holes in the top of the lens or anything but there must be a leak somewhere in the casing if it keeps happening.

Its diffusing the xenon beam on that side so it is quite annoying at night.

Any ideas anybody? Thanks in advance!

[PsYcHe]

I'd check the seals, and maybe run something round them to re-seal it.

Also check for hairline cracks in the lens, that seems to be the problem with my rears.

[Architex_mA8tey]

when you have condensation like this inside the glass it is because moisture / humid air has got into the lens and is then condensating on the inner face when its colder outside. You need to -
a) stop the moisture getting in at all (psyche's post about the seals) and
b) dry out the inside before you seal it up so there's no moisture in there to condense onto the glass.

If neither of these works when youve tried it then the only other option is to ventilate the headlight void space (which is why some people suggest drilling holes) but in practice you need to drill it in the right place and ensure enough of a flow of air to keep the inside dried out.

Failing both those then give A8 Parts a ring and see if they've got a better headlight in stock, or order a new one

[Conquistador]

I'm sure it doesn't help the situation when the headlight jets spray a wave of screenwash on the lenses of which some shoots up into the crack between the top of the light and the bonnet. I'll have to do some searching for the leak then.

[David's8]

Having just taken my (D2) lights completely apart to clean and polish (as per Iyole's excellent post), its worth mentioning that those units are not completely/permenantly sealed. When taking off the rear access covers to replace lamps or whatever you allow ambient air to enter the unit. The side/parking lights on the D2 Bi-xenon units are just loose/push fit and so there is ample space for ambient, moist air to get to the front of the unit and, when the covers are replaced, to remain there condensating on the front lens whenever the outside air gets cold.

Try venting the unit by removing the rear access covers and blowing through on a cold dry day. (we seem to be having a few of those at the mo')

[Iyole]

Agree with David ..... these are not sealed units ....

My suggestion would be to dismantle and dry everything out with the SO's hairdryer.
Then re-assemble making sure that the lens is properly seated/sealed on the headlamp casing....

Good Luck.