Fan Blower problem

[filip00]

okay, so here's my problem. the car is 525i 11/'90. the car has been maintained, but i can say now it's going thru the process of repairing and making EVERYTHING work. so, the next thing is fan blower.

it only works on position 4, and sometimes doesn't want to work at all! at position 4 it still isn't blowing as hard as it should. i've read it might be controller problem, but i didn't manage to find which type of controller i have and what i should open or try to fix.

here are some pics how it looks under the tapestry.

thanks for help.