AC/heat blower fan only stays low, nav screen stuck half way

[baloo]

We have a 2007 Z4 3.0si.
The other day, I went out to the car and the battery was dead. THe Nav screen was stuck half-way open.
Since it had the original battery, I replaced the battery, and it started and drove. HOWEVER, the nav screen remained half open, and there was only low speed AC/heater fan and some other AC/heat controls seemed funky. The radio worked, as did everything else.

Well, we didn't drive the car for 2 days, and when we went out, the battery was dead again.

I read some old DIY posts on the internet, and the "final stage resistor" seems to be a common cause of this kind of problem, including draining the battery.

I checked fuses, but darn if some of those European "universal language" symbols are more cryptic than hieroglyphics! I did not check all the fuses -- maybe two or three.

1) So, does anyone have a quick diagnosis?
2) Is there a single fuse that could cause the screen/fan problem?
3) If it's the FSR, where is that thing located?
4) Is there something I could disconnect to prevent the battery from discharging -- short of disconnecting the battery every time?

I checked our host's on-line parts catalog, and no FSR is listed for this car.

Anyone?
Thanks.