2012 nissan maxima
Burnt out hid xenon low beam headlight replacement turns out to be caused by moisture in the head light housing. And it wasn't the bulb that wasn't working it was the ballast full of water. I unscrewed the ballast from the bottom of the hl housing and took the ballast apart. Blew it dry with the compressor and let it sit in the sun all day. While I had the head light ballast out I used my compressor to blow out the headlamp housing so it was dry. I put the ballast back, reinstalled the headlight housing and thankfully my low beam xenon hid bulbs are working again. I also went ahead and changed the bulbs in both lights because don't wanna have to remove the bumper again anytime soon.

 

Great Job but did you find out how water was entering the HL assy? If not corrected, you will be doing this again! You may want to bite the bullet and install a new HL assy! Probably two! As I imangine they are getting pretty hazy by now.

 

I experienced something similar on my old Cutlass once. The left rear taillight housing would somehow develop moisture and over time it became 1/3 full of water, it was coming fairly close to the bulb before I noticed it. It was fairly straight forward to remove the whole housing (those were the days) and empty out the water, but just like LtLeary mentioned, it would be just a matter of time before it would do it again. So while i had the housing out, I drilled 2 very small (1/8") holes at the bottom of the housing. This not only help equalize the temperature in and out, but in the event of moisture buildup, any water buildup would drain from either of the holes i drilled. Worked perfect until I sold the car 20 years later.

 

I ended up using some waterproof tape to seal the crack I found in the top of the headlamp housing. I also threw a couple of those moisture absorbing pouches inside the housing behind the bulbs. It's been over a year now and so far so good. No leaks and no more moisture.