My '97 528 is not blowing any air regardless of settings. It had previously been making a whining sound. At that time (couple months ago) my Final Stage Unit was replaced and everything was OK. Now once again, there is no air. I assume it is the assembly that holds the blower wheels. Could anyone tell me where this part is located? Is it inside the car near the FSU or somewhere else? How difficult to replace myself?
Thanks!

I know for certain FSU, akas FSR could go wrong more than twice in a year. You say that you already replaced FSR. However, did you replace with the NEW MODIFIED FSR that was recommended by the BMW or replaced with the ORIGINAL FSU?
The original FSR is pretty heavy, larger in size with grey pins compared to the new modified one which is lighter, smaller and silver pins (looks like an hedgehog).
To my knowledge, the FSR is the biggest culprit that cause problems not only with climate control but also dead battery. So check the FSR regardless of replacement.