I found that the breather ( on the bottom, looks like a little can with slots) allows water vapor to be drawn up into the light where it condenses on the interior of the lens. The drain ,which is obvious, is to high up in the parking lamp area, to do any good. I plugged the breather with plumbers putty and drilled a small hole under the plastic ledge at the 8 o'clock position to allow the lamp area to drain and breathe. Guess what, it works.