hvac controls

I'm still not familiar with DSM. The vent selector knob to select air flow at dash or floor or defrost doesn't seem to do anything. In my Pontiac you can hear the vacuum changing the ventflow. In the spyder nothing happens. Only the slider to recirculate or pull outside air in seems to work correctly. I know that each vent can be closed but does the selector do anything?

1998 spyder gs

???

Try to take the knob off and see what is going on behind there

sounds like maybe one of the manual(not electric) wires isnt hooked up right? i agree take that fucker apart and scope around..its not that hard though