S10/T10 Blazer 2WD V6-262 4.3L VIN Z (1994)
Air Door Actuator / Motor: Initial Inspection and Diagnostic Overview
With A/C
Vacuum supplied by the engine is used to control various components in the Cruise Control, Deluxe Heater, and A/C-Heater and Engine Control.
The Vacuum System consists of a fitting on the intake manifold, a Check Valve, a Vacuum Tank, various Vacuum Solenoids, Vacuum Selector Valves,
and the connecting rubber and plastic hoses.
Vacuum is created in the engine during closed throttle and part throttle operation. During wide-open throttle operation, little, if any, vacuum is present in
the engine. A Check Valve is used in the main vacuum hose connected to the intake manifold to prevent loss of vacuum in the various systems during
wide open throttle operation.
The Vacuum Tank stores excess vacuum. The Reservoir provides this vacuum to the various systems when the Check Valve is closed during wide open
throttle operation.
Vacuum in these systems is used to position the various doors to control the flow of air through the plenum assembly. The doors are connected to
vacuum actuators. The Vacuum Selector Valve directs vacuum to these actuators to open or close the door.
Without A/C
Vacuum supplied by the engine is used to control various components in the Cruise Control, Deluxe Heater, and A/C-Heater and Engine Control.
The Vacuum System consists of a fitting on the intake manifold, a Check Valve, a Vacuum Tank, various Vacuum Solenoids, Vacuum Selector Valves,
and the connecting rubber and plastic hoses.
Vacuum is created in the engine during closed throttle and part throttle operation. During wide-open throttle operation, little, if any, vacuum is present in
the engine. A Check Valve is used in the main vacuum hose connected to the intake manifold to prevent loss of vacuum in the various systems during
wide open throttle operation.
The Vacuum Tank stores excess vacuum. The Reservoir provides this vacuum to the various systems when the Check Valve is closed during wide open
throttle operation.
Vacuum in these systems is used to position the various doors to control the flow of air through the plenum assembly. The doors are connected to
vacuum actuators. The Vacuum Selector Valve directs vacuum to these actuators to open or close the door. Refer to the Vacuum Selector Valve
Operating Charts to determine when vacuum is applied to the actuators
Cruise Control System. See: Symptom Related Diagnostic Procedures
