[fhofstra]

Jpar -
Try searching the forum using "climate control vents", or something similar. There's quite a bit there.
For your problem, there was some agreement from other posters that low A/C freon level could cause your symptoms. The fix was a freon (I guess I mean R-134) recharge.
I myself have a different issue - the driver's side blows colder than the passenger side when I set the A/C to cold, but the driver's side blows warmer than the passenger side when temp is set to hot. So the passenger side just reacts less across the whole spectrum.
The passenger-side actuator motor assy looked OK; I took it apart and didn't see any broken gears like poster "cougar" found.
I'd better stop and get my own thread before I hijack yours. Good fortune with it.