I have condensation in one of my tail lights. You can see it on the clear lens part. Do I have to take the whole light apart to get it out? If so, how do I go about doing that? By the way I have an '03.

 

I had that problem with a headlight assembly on my Grand Marquis. I removed the whole head light assembly, (be careful NOT to touch the glass bulbs or they will burn out quickly from the oils on your fingures), and sealed all around the connected pieces of the unit with windshield sealer (in a tube). I took the small electric air pump I have to inflate an air matress and placed the air hose into one of the bulb holds and let the air pump run for approx 20 minutes. (It depends on how much humidity is in the air that day). The air flows into the lens unit from one bulb hole, and flows out through the other bulb hole. After all the moisture was removed, I assembled the unit again and have had no further problems with it. Again, don't touch the bulbs.

 

yah you can seal them with silicone around them, but with the rear tails you dont need to worry about touching the bulbs, that only matters for fog lights and headlights, the 3157 bulbs can be touched, they dont burn that hot, and as for headlights how everybody screams dont touch the bulbs, if you do, just clean them with windex and paper towel, and you'll be fine

just take them off, clean them out, make sure they're dry when you put them back on, and the best thing to do is to but a bead of silicone around the light sockets, that should keep all the air out of them, you dont need to put it around the entire assembly

 

Ok, Wiz: Good info. My Merc headlight assembly was two plastic halves glued(?) together. I had to put the silicone around the whole unit.
As to fingures, I know, it's fingers. That's what lack of sleep does to one's ability to spell.

 

Keep an eye out for hairline cracks too. A friend had that problem. I think he put RainX or something in and while it didn't stop the water getting in, it rolled to the bottom of the light. Silicone fixed the problem in the end as well.