I'm bumping this thread, because it's such a great fix (I hope). Coincidentally, my passenger side fog lamp had a LOT of moisture. When I pulled it, I found it was cracked, probably due to someone munching into a snow bank or something. I sealed the crack with epoxy and reinstalled it. Had moisture the next day! I figured the seal around the bulb base may not be good, so I bought new O-rings and reinstalled it... still have moisture! When my wife gets the truck home, I'll try and find that sticker. If it works, this thread will get another bump.
Edit: My wife got the truck home, and I pulled the lamp:
No wonder it isn't breathing:
I won't bump this thread again. I didn't realize everybody else in the world must have already seen this but me!
Edit II: No, this didn't do the trick, so I did some more research. I believe that fabric I pulled off is "Gore Tex". When the lights are turned off, the inside of the lamp cools causing a vacuum to draw outside air in. If the air is moist it fogs up inside. The Gore Tex fabric allows air in without the moisture. I don't think the O-ring on the bulb socket can seal 100% due to the high vacuum created. Unless that base is sealed with silicone it can't be a truly sealed unit.
My next attempt will be to find a new piece of Gore Tex to cover that small vent in the top. My theory is the piece I pulled off was clogged by the glue used to hold it on, and air was being sucked in from the bulb's base instead.
Edit III: No Gore-Tex to be had locally, so I cut a small piece of "Omni Shield" fabric from my Columbia jacket. Hopefully it will perform like Gore-Tex.
Here is my quick method for removing moisture from the lamp:
To compress the tabs holding the lamp in the bumper, I use three 1/2" long sections of 1/2" copper pipe:
Only epoxy I have lately is JB Weld, so I used that to attach a small rubber washer with 3/8" hole around the 1/8" vent in the lamp:
We'll see if that does any good soon...
Edit IV: This ain't gonna work. "
Omni-Shield" is waterproof. Their fabric comparable to Gore-Tex is "
Omni-Wick Evap".
So, I'll put the lamp back in and wait till I get some real Gore-Tex fabric. If my theory is right, I won't see any moisture in the lamp as long as I don't turn on the fog lights...
Edit V: Well, my theory must be a steaming pile, because the lamp is steamed up within a few hours and I didn't turn them on.
I think I can buy a replacement for $30.00 shipped...
...yep,
my problem is solved for $31.57. Good luck to everybody else!