Can anyone shed more light on the various components on the back of the headlamp assembly?

Pun Intended

Currently dealing with the moisture-in-headlight problem that seems endemic to these assemblies, and having read all the threads I could find around these parts on the topic.

My question is, does anyone know more about what these various things are on the back? There are two gear-like bolts (one of which is even capped to prevent turning, I presume?) and then two white caps which have a cushion insert.



Mostly just curious--thanks!

 

Headlight adjustment screws.

-J

 

@chockomonkey Are your headlight buckets stock or aftermarket? Also, check the rubber boot that the light sockets snap into. I have 3 on my headlight assembly, side marker, turn signal and the headlight. In case you're wondering.

 

The moisture issue is unrelated to any of those items you see on the back of the light - unless you're actually submerging the light in water. Otherwise, it's almost always water getting between the housing and lens. But as mentioned, if the seals are missing or damaged you could get water in thru where the bulbs enter the housing. The headlight bulb will have that large rubber cover and the other two will have integrated rubber o-rings I believe. Aftermarket lights are known to leak. OEM ones are much less likely to leak and will probably only do it after a good amount of time has passed whereas aftermarket often leak when brand new.

Other than buying new lights the solution is to pull the housing and lens apart, remove the old sealant and apply new sealant. To do this properly the light must be taken apart, don't expect to just add sealant at the seam with the headlight still in one piece. DO NOT use products like silicone caulking you bought at Home Depot. The proper sealant is "butyl rubber":

$22 Morimoto RetroRubber OEM Grade Butyl Headlight Sealant, Black A330

https://www.amazon.com/RetroRubber-Grade-Butyl-Headlight-Sealant/dp/B01N5PM29J
https://www.diodedynamics.com/butyl-headlamp-sealant.html

 

Thanks everyone! I'm pretty sure these are OEM assemblies based on the various photos I've seen around. The reason I was looking on the back to begin with was a couple mentions in these moisture-issue threads related to popping off caps on the back to let things dry out.

I'll take off the boots (only have these on the main headlamp) and bulbs to inspect the quality of the seals and go from there. It's been SUPER hot and dry up here in the Puget Sound so I'll probably just leave the bulbs out to help let things dry out.

Are the white caps helpful for drying out at all? What purpose might those serve?

 

I’ve been dealing with the same issue with my passenger side headlight. I tried everything even drilling holes in those little white caps. I also drilled a few holes in the bottom of the headlight hoping that would help dry out the condensation inside the headlight. Mine are aftermarket TYC brand.

only thing I might try at this point is silica gel packs or a brand new headlight.

 

Adding holes will probably only make your issues worse. The correct solution, as I mentioned, is to separate the housing from the lens and then reseal it.

Until you reseal the lens you’re going to keep getting water inside and your addition a holes aren’t going to do a good enough job getting moisture and more importantly, water vapor, out of the light.

 

Makes sense. Thanks for the insight

 

^^^ This!

There are few products more over-used and inappropriately chosen than room temperature vulcanizing (RTV) silicones. It's a marginal sealant, a miserable adhesive, and it can prevent other materials from adhering properly once it's been tried.