Here's what I'm going through....
Dead aux fan > condenser can't keep up > high side pressure rise > compressor purge > pressure switch sees low refrigerant > compressor clutch will not engage. That's what's in my head... I could be wrong on that cascade theory, so here's a link:
http://www.princeton.edu/~sdepasqu/bmw/pdfs/AC.System.pdf
Currently awaiting new aux fan, proper refrigerant vacuum/recharge service, and test operation. But hey, at least the window regulators work! lol