Check stop lamp - third brake light out
 

The high mount lamp on my XC90 has been out of commission for a while now. My original had a crack in it and was filled with water. That made it pretty obvious as to why it wasn't working. I was able to determine I was getting power to the plug and figured I just needed a new high mount assembly. Found one on eBay, replaced it, and to my surprise it still doesn't work. I'm very confused now.

I've read of people having brake relay issues but that seems to cause ONLY the high mount light to work and knock out the side brake lights. Mine is the opposite. Side brake lights are perfect, the high mount is out.

Any ideas or suggestions would be greatly appreciated! Thanks!
First step is to verify my replacement is working. It was in the pics but we all know how that can go.

*** UPDATE ***
Would love to tell you guys I did some fancy schmancy electrical engineering feats and fixed this. However...it just started working on it's own. No idea why, don't care, works fine now, lol.