Blower Motor Duct Not Opening 1991-88

Has anyone ran into this one?

It appears that the heater/AC blower motor is working on all speeds.
The problemis is that the air is only trickleing out of the three vents (defrost, middle and lower). It seems to me that a major vent duct is not opening. I have looked at fuses and possible broken air line with no luck.

Thanks in advance,
Jersey Tomato Man

There is a mixer door actuator (I think that is the part name) that has probably died or the metal arm has slipped out of the motor. This is located behind the dash on the passenger side, behind the glovebox.

There was a thread on this recently...I think it was over in the Park Avenue forums. I'll see about finding tommorow since I'm going to bed...

Edit: Found it. This may help: http://www.automotiveforums.com/vbulletin/showthread.php?t=419903