i bought a pair of headlights and ballast and bulbs from a user on here and her said he never had an issue with the lights and humidity or anything. well i got the light installed them, and had to use my seals from my old headlights. you know the ones behind the hid light and the smaller one that seals up around the daylight... also the ballast was loose and not screwed in so i had to use my old ballast mounts.. what im asking is would most likely be getting humidity from where the ballast sits? should i seal it back up with a new gasket? or that make your own seal stuff? lights looks good and everything worked fine the balast that came with the light looked rusted but worked with no issues.. thanks for an input.. my tl is a 2005

 

There are definitely seals there, I did some reading on this before as I had this problem as well in one of my headlights after changing the HID bulbs.

If all the seals are good and there is moisture trapped inside it'll keep doing it, so here's what I did..

- Remove the fog bulb
- Disconnect the HID power connection
- Remove the gray HID power connector (not completely, it has wires running through it)

- Using a heatgun blow hot air into the hole where the fog bulb was
- Using a vacuum suck air out of the hid power connection hole

That got most of the moisture out of my headlight .. it still fogs a very small amount though.. not sure how they really seal these up once they're open but if a seal is bad or it gets some moisture trapped inside in the form of humidity it'll condense on the inside of the lens due to the temperature difference (hot inside the assembly, cold outside).