Ventilation Air Flow System

Specified Air Flow Patterns:

1. With the ignition switch ON and the blower motor switch set to position HI for maximum air flow, check the air flow patterns resulting from the position settings of the air flow selector lever. Verify that they conform to the Specified Air Flow Patterns chart.




PANEL




PANEL/FLOOR




FLOOR




FLOOR/DEFROST




DEFROST




Recirc or MAX A/C

2. If air flow patterns do not conform to the specified patterns, repair, adjust, or replace the outlet doors or components as required.

Specified Air Flow Movement (Air Intake):

3. With the ignition switch ON and the blower motor switch set to HI position for maximum air flow, change the function selector switch setting from MAX A/C to any other position. Verify that the air movement conforms to the specified patterns listed in the Specified Air Flow Movement (Air Intake) chart.






4. If Recirc/Fresh air does not conform to the Specified Air Flow Movement (Air Intake) chart, proceed with the following tests:
^ Disconnect the function selector switch connector and check for vacuum with the engine running.
^ If no vacuum is present, check the vacuum supply for leaks or damage. Replace the vacuum check valve, vacuum lines, or the vacuum reservoir as necessary.
^ To check vacuum availability in each function. "V" indicates vacuum is available and "NV" indicates that no vacuum is available.
^ If the vacuum availability is not as specified, inspect vacuum harness connections for poor fit, deterioration or kinks. Repair or replace as necessary. Otherwise, replace the function selector switch.
^ Disconnect the vacuum control motor and apply vacuum with a vacuum tester. The A/C air inlet door should open as vacuum is applied and close as vacuum is released. If the A/C air inlet door does not move properly, check the linkages for kinks or damage. Repair or replace linkages as necessary. Otherwise, replace the vacuum control motor.
5. Disassemble the following components of the ventilation system for inspection as required, and remove any foreign material causing air flow blockage:
^ A/C blower motor.
^ A/C evaporator housing.
^ Recirculation inlet.
^ Fresh inlet.
^ Main air duct (no A/C).
^ Evaporator (with A/C).
^ Heater core inlet side.
^ Air outlets at floor, panel, and defroster.
6. If air flow is inadequate in any position, adjust the A/C air inlet door, defrost/floor control door, temperature control door, or vent function control door as required. Otherwise, return to the pinpoint tests. Pinpoint Tests