A/C Vacuum Solenoid Module
WARNING: This page is about a different car, the 1997 Oldsmobile Cutlass Supreme. However, it is still accessible from the selected car via links, so may be relevant.
Vacuum solenoid module converts electrical signals from A/C-heater control unit microprocessor into vacuum commands to position mode, A/C-defrost, and outside air valve in air distributor assembly. Vacuum is constantly applied to module, which distributes it to 5 solenoid-controlled valves in module.