Headlights fogging up on the inside?

[iSamage]

Noticed lastnight whilst I was out, just filled up and walking back to the car, the drivers headlamp is fogged up on the inside. Thought it would go away by morning but just been to my car after being left for a few hours and it's still there. I didn't use my headlights this morning.

I do have a HID Xenon kit installed, with LED sidelights but surely if that was the problem then the passenger side would be doing it too?

Is there any particular reason/fix for this? Car is with the dealer in a week to remove some scratches they put on it during servicing so could mention it then but don't think it would get me anywhere. I do a lot of night driving, thus the HID kit, so this is really playing on my mind.

[Prykey]

My only thought would be the "seal" on the back of the headlamp where your wires for the HID kit pass through this need to be as good as the original seal before you converted to HID as the rubber covers fit pretty tight and you have now probably cut holes in them to pass the wiring for the HID units through.

[dieselV6]

First and foremost, dry the lamp inside - in good weather, remove the caps at the back and either leave the car front facing sun or use hairdryer at a safe distance. Secondly, identify which way water enters the lamp.

 

You mentioned HIDs, is the ballast inside the lamp (some very small ones fit) or outside? If outside, a common way for water to enter is through the grommet, either crack, or incorrect fit, or if cables outside headlamp point upwards and force water in (cables should drop downwards outside headlamp, after drop they can be routed any way needed).

 

If HID install is not the reason, another common ingress point is the indicator bulb seal, double-check it is sealed properly.

 

In any case, do not wait for long before fixing it, as water will corrode bulb connectors quickly (when headlamps are in operation).

Edited 7 October, 2014 by dieselV6

[fabiamk2SE]

My only thought would be the "seal" on the back of the headlamp where your wires for the HID kit pass through this need to be as good as the original seal before you converted to HID as the rubber covers fit pretty tight and you have now probably cut holes in them to pass the wiring for the HID units through.

Id agree.

I had a similar issue. Only slight fogging but i put some silicone grease around where the hid grommet goes through, and its been fine ever since

[silver1011]

Some light misting inside the headlight and foglight/DRL is allowable, it is mentioned in the manual.

Yours looks to be excessive though suggesting a problem.

The obvious issue lies with where and how the HID kit wiring enters the headlight.

However the headlight also has a breather tube on the back to allow moisture to escape. After prolonged periods of wet weather and if driving through puddles or standing water moisture can also enter the headlight through the tube.

A quick fix will be to drive with your headlights on, this will quickly dry them out (the moisture evaporates through the breather tube) but if the problem is elsewhere then the issue will quickly return.