Blower Fan Won't Turn OFF

[OverkillGarage]

Recently purchased '08 550i MSport has a few quirks I'm trying to resolve.
First on the list is the odd hvac blower fan operation:
Initially the fan would not turn on
At some point the fan turned on and will shift temperature from control panel
Fan will not change speed and will not turn off after key off
I've swapped the control panel from another E60 with no change
Nothing I can see in the iDrive menus are driving this behavior
Could a bad blower resistor (aka final drive) or fan cause this? I'm not finding much out there on this unfortuantely.

Thanks for any help provided!