2002 Z71 Recirc Button Question?

I need some help defining what happens when the "Recirc" button is activated when both the HVAC system and fan are off.  I seem to recall that when I pushed this button, when both the fan and HVAC systems where all turned off, that I would hear the damper close and no air would pass thru the vent ducts.

Currently I push the button and the vents still have air passing thru them in to the cab and I no longer hear the damper door move or close..

Can anyone confirm or deny what I used to think happened with the damper and if it is supposed to stop air venting?  If it is supposed to stop any airflow what might be wrong now?

Thanks everyone.

Courtesy or the 2002 Owners Manual Sec 3 page 6 in the Resources tab to your left. 

(Re-circulation): Press this button to limit the amount of outside air entering the vehicle to a very small amount. This will be helpful to limit odors entering the vehicle and will assist in reaching comfort in very hot temperature conditions. Pressing re-circulation will cause the system to recirculate interior air continuously and may cause the vehicle windows to fog if the passenger compartment floor is excessively wet.
Pressing the re-circulation button will cancel outside air operation. To return to normal system operation and to prevent stale passenger compartment air, be sure to return to the outside air position.
Re-circulation will not be available in floor, blend or defrost modes to help reduce window fogging. If the re-circulation button is pressed in theses modes, the LED indicator for re-circulation will flash three times indicating that forced outside air is activated and re-circulation is not available.
If the air conditioning system is activated and system demand is high in situations such as city traffic, idling, or very hot weather, the system will automatically switch from outside air to re-circulation. The LED indicator will not change. After demand on the system is not so great, the system will return back to outside air.

IF AC is off it will not do anything...

It defualts to outside air to ensure fresh air in cab and no CO poisoning.

Thanks for the information all.