Solenoid Valve
WARNING: This page is about a different car, the 1995 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
Remove solenoid valve. Blow air through port "B". Ensure air flows from valve air filter. Connect 12 volts and a ground to solenoid valve terminals. Blow air through valve port "B", and ensure air flows from port "A". Replace solenoid valve as necessary.