So I noticed after a few days ago that my right headlamp assembly had A LOT of condensation / moisture inside. The inside of the lens was completely covered in water droplets. The solution to this typically seems to be opening the whole headlamp assembly and re-sealing it, which I wasn't looking forward to!

Then I remembered that I had recently attempted (and failed) to replace the little "marker" lamps inside the headlight cluster, and the timing seemed suspect. So I opened the hood up and lo and behold... there's a funny t-shaped rubber pipe that I remember removing during my aborted efforts to replace the bulb, and it's MISSING on the side that's getting the condensation! Not sure if I forgot to re-install it or if it just cracked or slipped off afterward. (I remember thinking the rubber felt dry and brittle.)

I looked all through the service manual and there's no mention of this little gubbin, nor does it have a part# stamped or molded into it. Based on the design, it seems plausible to me that it probably plays some role in preventing condensation, and it would certainly explain why I'm having this issue now. Anyone got any ideas where I could source a replacement?

 

For those hard to reach lights you can order long forceps on Amazon that will reach and grip them. I believe the hoses are to allow the headlights to breath without letting water get in through the opening. I have never heard of anyone successfully opening up the lights and resealing them.

 

Once upon a time, there was a seeming problem with condensation building up inside the headlights, I had a very small build up in mine. This disappeared when the lights warmed the headlight interior.
Others believed water was inadvertently diverted to the interior via leaks in the seal or the part you are missing.
Whatever the cause a kit was made available for some small cost to solve the problem, I purchased and fitted the kit. I never saw any signs of condensation again. You cannot buy this kit for some time now.
There are threads on this forum that explain how to dry out the headlight.

Half of the kit required for one headlight, there may only be one cap per headlight, I have forgotten.


A headlight with the kit fitted.

 

Interesting... thanks for the insight! I looked in my toolbox and, sure enough, there was the little rubber t-pipe that I forgot to reinstall. I put it back on this evening and I guess we’ll see what happens.

I never had a drop of moisture inside the assembly before now in the 10+years I’ve owned this car, so hopefully just running it with the headlights on will evaporate out any moisture that’s collected.

 

I have had some condensation in the past. I used a hair drier on low aimed into one of the headlights with the rubber cap removed (with the other cap removed to allow airflow throughout). Running this for a couple minutes then re-capping the lamp holes took care of the moisture inside. Good luck!


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So just dry it out and cap that hole.

 

Update: the little rubber t-pipe was so old and brittle that it split when I went to put it back on. So I gummed it up with a bunch of silicone bathroom caulk (didn't have any RTV sealant handy) stuck it back on, and gave it a few hours to set. I dont have power in my garage and the hair dryer trick would have required a VERY long extension cord, so the next day I just left it sitting for a few hours with the headlights on, to encourage the moisture to evaporate.

It's been a few days now and the moisture is GONE. What a big difference a tiny rubber tube can make!

Seems like that part would be a good candidate for 3D printing if other people start to experience the deterioration of the rubber like I did.

 

Found this approach that seems to work and may be cheaper than the factory kit.