So I've noticed that lately when I wash my car or when its cold outside my headlight seems to get fogged up from what looks like to be moisture built up inside the headlight assembly unit. Anyone come across this problem and know how to fix it? Thanks in advance.

 

Is it both headlights? Are they both experiencing condensation equally?

Ever had the headlights off before? Somehow, somewhere, your lights are not 100% sealed. If you can locate the area that is not properly sealed, you can quick-fix it with some silicone sealant. Removing the headlights on this car takes about 5 seconds, so take them off and search for where it may not be fully sealed.

 

I would recommend searching for the air leak. If you don't then the build of the moisture could lead to rusting, reduced light on the road and headlight failure. I've taken many headlights apart in the past and have used many different processes to do so. The manufactures put on a very thin coat of the silicon/adhesive to bond the headlights together. When I painted the interior of my STi headlights I actually put the headlights in my oven for 15 mins on low heat. This allowed the adhesive to loosen up and I could pull the two pieces apart. After I painted the inside black, took all the old adhesive off and cleaned the area I re-applyed the black RTV silicon, pushed the pieces together, baked in the oven for 5 mins and then pressed the pieces together even further to make sure all areas are sealed and tight. Let it sit for half a day so the RTV will harden and seal. Then reinstall. This is a process that if not done right, you'll know in a few days. Don't use normal silicon, it doesn't have a adhesive quality you need to hold the pieces together. You need a gooey, sticky, almost tar like quality that sticks to plastic. Good luck. If you need a DIY thread from the IWSTI.com website I'm sure I can find it for you. Don't rush, take your time and do it right.

 

I'm pretty sure these lights are not supposed to be sealed... There should be a rubber extension on the air vent that looks like this:



Also, the adjustment screw for aligning the headlight kind of makes a perfect seal impossible. Keeping the light vented allows the equalization of air inside and outside so that there won't be any accumulation of moisture within the light. I would check your assembly to make sure your vent(s) is/are in place and not plugged.

 

I'm new to my 911 but what slider said above makes sense. Allowing the air to go in and out would prevent moisture from staying in the assembly. Research is key. The reason why I bought my 911 is so I can learn about a car/manufacture that I never owned before. Germans do things different