2000 Venture: Little or no air from A/C ?

[ddiamondd]

My 2000 Venture outputs little or no air from any of the vents (defrost, heater or dash vents). I have changed the incoming air filters (located at the back of the glovebox), which only slightly improved the airflow. Upon further investigation, I have noticed that when I switch the control panel for moving air output for defrost, heater position or vent output, there is no change in the direction of where the air is coming from. I know that there is a motor or device which receives a signal from the computer to move a flap in the airbox depending on which position is selected. How do I fix this problem? I am capable of removing and replacing a lot of things on my vehicle, I just need a little help on the procedure.