Okay guys; it's been awhile for me but here I am with another question. My 89 735il AC works fine on the driver's side but the passenger side blows hot air. Is this a problem with the heater valve or the individual air distribution motors?
I would guess the Stepper (air distribution motors) or their mounts. Go to: http://bmwe32.masscom .net and look at the heating cooling items, particularly center vents.