Condensation in headlight

dickydido · 19th January 2007, 20:47

I have been having problems with condensation in my n/s headlight - after a poke around under the bonnet i realised that the rubber cover thingy that goes on the back of the light assembly (the larger one of the two) had disapeared sometime in the cars life and so this seemed a reasonable explanation for the condensation - so after half an hour with a hairdryer and a lash up with a piece of plastic bag and elastic band the lens was clear and sealed again - job done. But sadly no - 24 hours later condensation was back with avengance, I know it been monsoon season here the last week but i thought it might have lasted a little longer.

From those of you that may have had these things apart does it seem that I was just unlucky and didn't get all the water out or is it likely that something has expired, there are no visible signs of damage to the lens.

Simon · 19th January 2007, 21:30

It could be that your make-shift seal is not up to the weather conditions of late!

I'm sure Rimmer Bros will be able to suply you with a new OEM seal so it's worth trying one of those first. Damn sight cheaper than a new light assembly!

If the seal does not solve the problem then it may be a crack in the casing somewhere that is causing your problems. Getting at the headlight assembly requires removing the front bumper (see http://www.the75andztclub.co.uk/foru...read.php?t=204 for bumper removal)

Hope this helps!

JohnDotCom · 19th January 2007, 22:11

I get this all the time on my Front Indicators (FaceLift Model), Ive put new ones in then go exactly the same.

MN190 · 19th January 2007, 22:18

I get this on my lights from time to time and allthe seals are in place. Also have had it some of my previous cars and thought it was more to do with the short runs

direstraits · 19th January 2007, 22:24

This is a problem well known to marine peeps. It is caused by the air heating up in the light fitting and expanding.When the light is switched off the air cools down and draws in more moist air.When the air in the lamp assembly is so wet that it cant absorb any more it condenses on the glass. The cure is to allow the air to flow freely through the fitting. It sounds daft but that is way to cure it.Sealing the assembly tight is not the cure as the air must excape. On many of the automobile light fittings there was a small tube out the back that allowed this expansion.
It does not need a lot of moisture to cloud a lens, in severe cases the water can be seen lapping in the bottom of lamp assemblies. This is not always due to leaks.

dickydido · 20th January 2007, 20:56

Well 'direstraits' I think there is something in what you say - I left both the covers off the back today, didn't take long for the lens to clear and it certainly 'hissed' it down at one point - sorted

Cheers chaps

19th January 2007, 20:47	#1
dickydido Newbie ZT Join Date: Nov 2006 Location: New Forest Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	Condensation in headlight I have been having problems with condensation in my n/s headlight - after a poke around under the bonnet i realised that the rubber cover thingy that goes on the back of the light assembly (the larger one of the two) had disapeared sometime in the cars life and so this seemed a reasonable explanation for the condensation - so after half an hour with a hairdryer and a lash up with a piece of plastic bag and elastic band the lens was clear and sealed again - job done. But sadly no - 24 hours later condensation was back with avengance, I know it been monsoon season here the last week but i thought it might have lasted a little longer. From those of you that may have had these things apart does it seem that I was just unlucky and didn't get all the water out or is it likely that something has expired, there are no visible signs of damage to the lens.

19th January 2007, 22:24	#5
direstraits Avid contributor 2X MGZT-T190,s 1XMGZT180 X-PowerGrey/Trophy Blue/ Anthracite Join Date: Nov 2006 Location: Hampshire Posts: 114 Thanks: 0 Thanked 0 Times in 0 Posts	headlight condensation This is a problem well known to marine peeps. It is caused by the air heating up in the light fitting and expanding.When the light is switched off the air cools down and draws in more moist air.When the air in the lamp assembly is so wet that it cant absorb any more it condenses on the glass. The cure is to allow the air to flow freely through the fitting. It sounds daft but that is way to cure it.Sealing the assembly tight is not the cure as the air must excape. On many of the automobile light fittings there was a small tube out the back that allowed this expansion. It does not need a lot of moisture to cloud a lens, in severe cases the water can be seen lapping in the bottom of lamp assemblies. This is not always due to leaks.

19th January 2007, 21:30	#2
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	It could be that your make-shift seal is not up to the weather conditions of late! I'm sure Rimmer Bros will be able to suply you with a new OEM seal so it's worth trying one of those first. Damn sight cheaper than a new light assembly! If the seal does not solve the problem then it may be a crack in the casing somewhere that is causing your problems. Getting at the headlight assembly requires removing the front bumper (see http://www.the75andztclub.co.uk/foru...read.php?t=204 for bumper removal) Hope this helps!

19th January 2007, 22:11	#3
JohnDotCom * Rover 75 FaceLift Tourer CDTi 170BHP Auto ConnSE 2005 Model Starlight Silver Join Date: Nov 2006 Location: Abergele Posts: 28,735 Thanks: 0 Thanked 6 Times in 5 Posts	I get this all the time on my Front Indicators (FaceLift Model), Ive put new ones in then go exactly the same.

19th January 2007, 22:18	#4
MN190 Posted a thing or two MG ZT 190+ Join Date: Nov 2006 Location: North Norfolk Posts: 1,423 Thanks: 2 Thanked 11 Times in 11 Posts	I get this on my lights from time to time and allthe seals are in place. Also have had it some of my previous cars and thought it was more to do with the short runs

20th January 2007, 20:56	#6
dickydido Newbie ZT Join Date: Nov 2006 Location: New Forest Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts	Well 'direstraits' I think there is something in what you say - I left both the covers off the back today, didn't take long for the lens to clear and it certainly 'hissed' it down at one point - sorted Cheers chaps