My blower and CCU hate me!

[BullKatX5]

Long time searcher, first time poster. I'm at a loss here and have been Googling and searching this forum (and the bimmerfest.com forums) for a long... long time. This problem is going on in my 2001 E53 (4.4l).

In a nutshell: my climate control unit is not working (no lights or controls), and my blower is always running full blast - even without the key in the ignition. I've pulled fuse 64 so the blower doesn't kill my battery. Additionally, and this may or may not be related, but without the CCU and blower there is still hot air blowing in the foot wells. The heat in the foot wells gets hotter as the engine gets hotter (we're talking melting-my-shoes-on-long-distance-drives-in-the-summer hot).

All of these issues happened at the same moment: I parked my car, went to turn down my heater and BAM! The climate control part of the module went full blast and could not be changed, and the blower went crazy. Turned the car off then back on "just in case" and the module was dead (blower still going this whole time). I pulled the fuse and... now I am where I am.

Possible solutions I've already tried:
- Replaced FSR this past winter (had overnight battery drain and some erratic heat issues; FSR replacement solved these problems)
- Checked all fuses related to the A/C and blower units/systems - no blown fuses
- Replaced the climate control module (this needed to be done anyway because the screen was busted)
- No errors on the OBD reader

Any other suggestions as to what I could check? Could the new FSR be defective (and is there a way I can test it)? I want to try as many potentially simple solutions before I spend more money on another FSR...

TIA