Headlight condensation

[Don Winter]

Hi
One of my headlights suffers permanently from condensation.
Any advice on cause and cure please?
Many thanks.

[Brendan W]

Water getting in somewhere obviously.
Usual suspects are a failed seal at the front cover or at the covers for the bulb holders at the back.
Some cars have resorted to a permanent vent drilled in the back with either a 90 degree elbow with tube or a piece of breathable fabric glued over the hole.

[oragex]

I fixed the issue years ago by removing the thin plastic cover that runs on top along the seam between the glass and the housing, them apply a thin coat of quality outdoor silicone film.

[boggymarsh]

A very quick, cheap and simple solution is to drill a 10mm hole in the black plastic cover that you remove to replace the head lamp bulb. It’ll take a few days to sort itself out but you’ll never have condensation in the lense unit again.

I’ve did my V70 some ten years ago and more recently when I bought my XC70 and have never had a problem since.

[jasmith44]

Originally Posted by boggymarsh

A very quick, cheap and simple solution is to drill a 10mm hole in the black plastic cover that you remove to replace the head lamp bulb. It’ll take a few days to sort itself out but you’ll never have condensation in the lense unit again.

I’ve did my V70 some ten years ago and more recently when I bought my XC70 and have never had a problem since.

I second that I did it on my s80 and never had any problems after.

[ASt85]

Some models have the lamp cover fitted with that small strip of Gore-Tex type breathable material - you can often pick these up from a breaker for around a fiver - oddly my main beams had the fitted strip but the dipped beam didn't the near side would get condensation on a seasonal basis - although I now have the breathable fabric ones fitted over both lamp holders in each housing - the easiest way to get rid of the moisture is to run without the cover in place for a few days then use the drill hole method mentioned above NB put the drill hole on the lower side of the cover - it worked well for me until I could source the genuine covers.

[Roy V70 850]

Got the same problem on my 2004 V70. Firstly tried to dry it out by removing the bulb covers and bulbs and blasting air through it using a hair drier and an angled piece of drain pipe. This was when I discovered that the unit was full of water. So I used a glass drill (on slow) to drill a hole in the bottom corner of the headlamp glass to drain the water out. (couldn't believe how much water drained out)

Leaving the bulbs and covers off, the condensation disappeared. When I put them back, the condensation re-appeared. Removing the bulbs for another day cleared it again. The cluster obviously needs ventilation.

I will now try drilling holes in the covers and applying silicone to the top seal of the cluster (as suggested) to see if that cures the problem.

[Spike56]

Risky but worked for me...if you can cover the light with a cloth or something similar while you are driving (daytime obviously!) the heat generated is often enough to evaporate the condensation completely.

[oragex]

I did this a few years ago, very easy, perfect dry ever since https://www.youtube.com/watch?v=6slXpVWRQUQ