04 xc70 xenon headlights take water

[famfeld]

Hello all.
On my xc70 I have these cool looking clear glass (yet expensive) xenon headlights with a balasts that produce a bluish light. I don't see these same light on most similar era volvos, but they give the front a really modern look. About a year ago, both headlights were contaminated with water that eventually burnt out the balast and or bulbs. The glass was also cracked so i broke down and bought used pair from a local salvage yard for around $300. I couldn't find them cheaper anywhere and these were nice so i cut my losses. Before installing them i put clear silicone caulking around glassto plastic mating surface. I also used sealing tape (looks like electrical tape, but is soft and stretchy) to seal the removal caps that access the bulbs. After all that, a year later one has begun to get water in it. I replaced it with a a spare and removed the caps from the old one, so it will dry out, but wss wondering if anyone has any experience with these things or other's getting water in them. The salvage yard people told me they leek at the turn signal cap, but i believe i sealed it pretty well.

Any ideas or suggestions?

Thanks

Feld