any one got any idea what causes it and how to get rid of it?

any one got any idea what causes it and how to get rid of it?

It's normal, don't worry about it.

Yep, normal...

Like condensation inm your house it is caused by water molecules that have evaporated and become part of the (damp) air hitting a cold surface which then causes a change back into liquid form upon that surface (it condenses). In modern houses this is normally avoided by wall insulation and double glazing (where the space between the glass is a vacuum and therefore contains no moisture to condense.

So to stop it on headlights you would effectively need a vacuum within the light unit too avoid all water molecules being present - but this would be very expensive and make changing bulbs impossible without binning the whole light unit.

Anyway, if you have your lights on for any length of time the warmth from the bulbs should effectively 'burn' it off in the same way as the warmth from your heated rear window does (eg the molecules evaporate again), but in any case it does not affect the effeciency of the lights themselves.

.....

Anyway, if you have your lights on for any length of time the warmth from the bulbs should effectively 'burn' it off in the same way as the warmth from your heated rear window does (eg the molecules evaporate again), but in any case it does not affect the effeciency of the lights themselves......

Dont forget, if you havent got anywhere for the air to vent, it will just re-condence.

Best to take the back covers off (fog lights), or take your mainbeam bulbs out and drive round on dipped for a while.

Dave

drilled a really small hole on the bottom black plastic of the light. like opening a window in your house when it steams up lol. seems to have done the trick. cheers fellas

So to stop it on headlights you would effectively need a vacuum within the light unit too avoid all water molecules being present - but this would be very expensive and make changing bulbs impossible without binning the whole light unit..

Not quite, you would need to drop the dew point down below -20C and seal it - not possible with plastics.

Anyway, if you have your lights on for any length of time the warmth from the bulbs should effectively 'burn' it off in the same way as the warmth from your heated rear window does (eg the molecules evaporate again), but in any case it does not affect the effeciency of the lights themselves.

I think that the MOT even accept this - unless like me you accidentally mess up refitting the cover after changing the amber indicator bulbs - then give the car a really really good wash the day before the MOT - not very clever at all, that was what is really called condensation, I'll not try that trick again for a while ~(I hope).

could be caused by the cover not seated correctly

Next time you wash the car and the headlamps condense up,

Open the bonnet and leave open.

Unclip the headlight rear covers or remove the indicator bulbs & holders.

Start engine and leave idling (under supervision naturally)

Switch on headlights and fire on the main beam and leave for about 20 mins. This should burn off the condensation.

When cleared, Re-assemble lamps and use a couple of self tappers (Small ones, 4mm X 12mm max) to secure the back covers (There are two screw points on the covers on both sides, Badly circled below:rolleyes:) this should help. Won't completely cure it but goes a long way!

Ignore the Ballast!

All headlamp covers are the same!

Or next time you find some of the silica gel packets in shoe boxes etc, you know the ones that say DO NOT EAT on them save them and wedge them in the bottom of the lamp, this will suck up the moisture.

Or next time you find some of the silica gel packets in shoe boxes etc, you know the ones that say DO NOT EAT on them save them and wedge them in the bottom of the lamp, this will suck up the moisture.

i ate them instead :rotz: