Pinpoint Test H: Incorrect/Erratic Direction Of Airflow from Outlets - Manual Climate Control
Climate Control System
Pinpoint Tests
Pinpoint Test H: Incorrect/Erratic Direction of Airflow from Outlets - Manual Climate Control
Normal Operation
Under normal operation, the function selector switch is provided vacuum from the engine. When a position is selected, vacuum is applied to the desired vacuum control motor that is connected to the mode door it controls.
This pinpoint test is intended to diagnose the following:
- Function selector switch
- Vacuum control motor
- Stuck or bound linkage or door
- Leaking or plugged vacuum hose
PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLETS - MANUAL CLIMATE CONTROL
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H1 CHECK THE AIR FLOW IN EACH SETTING
- Ignition ON.
- With the engine running, set the blower motor speed to maximum.
- Check the airflow in each function selector switch setting at engine idle and under acceleration.
- Is the airflow from only the defroster outlets in each function selector switch setting?
Yes
GO to H2.
No
NOTE the non-functional setting. GO to H10.
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H2 CHECK FOR VACUUM AT THE CHECK VALVE
- Disconnect the vacuum check valve vacuum source line and check for manifold vacuum and connect the vacuum pump.
- Is manifold vacuum present at the check valve vacuum source line?
Yes
GO to H3.
No
REPAIR or INSTALL a new check valve vacuum source line. TEST the system for normal operation.
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H3 CHECK THE VACUUM CHECK VALVE FOR BLOCKAGE
- Reconnect the vacuum source line to the vacuum check valve.
- Disconnect the vacuum reservoir line and the manual climate control assembly vacuum line from the vacuum check valve and plug one port.
- Check for manifold vacuum at the open port on the vacuum check valve.
- Is manifold vacuum present at the open port on the vacuum check valve?
Yes
GO to H4.
No
INSTALL a new vacuum check valve. TEST the system for normal operation.
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H4 CHECK THE VACUUM CHECK VALVE
- Ignition OFF.
- Connect the vacuum pump to the open port on the vacuum check valve and attempt to pull a vacuum.
- Can a vacuum be pulled on the vacuum check valve?
Yes
GO to H5.
No
INSTALL a new vacuum check valve. TEST the system for normal operation.
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H5 CHECK THE VACUUM RESERVOIR LINE FOR BLOCKAGE
- Disconnect the vacuum reservoir line at the vacuum reservoir.
- Connect the vacuum pump to the vacuum reservoir line at the vacuum check valve connection and attempt to pull a vacuum.
- Can a vacuum be pulled on the vacuum reservoir line?
Yes
REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation.
No
GO to H6.
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H6 CHECK THE VACUUM RESERVOIR LINE FOR LEAKS
- Plug the vacuum reservoir line at the vacuum reservoir connection.
- Leak test the vacuum reservoir line using the vacuum pump.
- Does the vacuum reservoir line leak?
Yes
REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation.
No
GO to H7.
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H7 CHECK THE VACUUM RESERVOIR FOR A LEAK
- Connect the vacuum pump reservoir line to the vacuum reservoir.
- With the vacuum pump connected to the vacuum reservoir line, leak test the vacuum reservoir.
- Does the vacuum reservoir leak?
Yes
INSTALL a new vacuum reservoir. TEST the system for normal operation.
No
GO to H8.
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H8 CHECK THE FUNCTION SELECTOR SWITCH VACUUM SOURCE LINE FOR BLOCKAGE
- Disconnect: Function Selector Switch Vacuum Connector.
- Connect the vacuum pump to the function selector switch vacuum source line and attempt to pull a vacuum.
- Can a vacuum be pulled on the function selector switch vacuum source line?
Yes
REPAIR or INSTALL a new function selector switch vacuum source line. TEST the system for normal operation.
No
GO to H9.
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H9 CHECK THE FUNCTION SELECTOR SWITCH VACUUM SOURCE LINE FOR LEAKS
- Plug the function selector switch vacuum source line at the vacuum check valve connection.
- Leak test the function selector switch vacuum source line using the vacuum pump.
- Does the function selector switch vacuum source line leak?
Yes
REPAIR or INSTALL a new function selector switch vacuum source line. TEST the system for normal operation.
No
INSTALL a new function selector switch. REFER to Climate Control Function Selector Switch. TEST the system for normal operation.
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H10 CHECK THE FUNCTION SELECTOR SWITCH FOR BLOCKAGE
- Disconnect: Function Selector Switch Vacuum Harness.
- Connect a vacuum pump to the function selector switch vacuum supply port and try to pull a vacuum in each function selector switch position. If the vacuum pump can pull and hold a vacuum, the switch is plugged. If the vacuum pump pulls a vacuum that slowly decays, the hose is restricted.
- Is the switch plugged or restricted?
Yes
INSTALL a new function selector switch. REFER to Climate Control Function Selector Switch. TEST the system for normal operation.
No
GO to H11.
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H11 LEAK TEST THE FUNCTION SELECTOR SWITCH
- Connect a vacuum pump to the function selector switch vacuum supply port and plug each control port.
- At each function selector switch position apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum drop exceed 3.37 kPa (1 in-Hg) per minute?
Yes
INSTALL a new function selector switch. REFER to Climate Control Function Selector Switch. TEST the system for normal operation.
No
GO to H12.
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H12 CHECK THE VACUUM HOSE
- Disconnect the vacuum line from the appropriate vacuum control motor noted in Step H1.
- Connect the vacuum pump to the appropriate vacuum control motor line noted in Step H1 and attempt to pull and hold a vacuum.
- Does the vacuum in the line drop exceed 3.37 kPa (1 in-Hg) per minute?
Yes
GO to H13.
No
GO to H14.
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H13 CHECK THE VACUUM CONTROL MOTOR
- Disconnect: Vacuum Control Motor.
- Connect a vacuum pump to the affected vacuum control motor. Apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum drop exceed 1.68 kPa (0.5 in-Hg) per minute?
Yes
INSTALL a new vacuum control motor. REFER to Climate Control Service and Repair. TEST the system for normal operation.
No
REPAIR or INSTALL a new vacuum harness. TEST the system for normal operation.
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H14 CHECK THE VACUUM CONTROL MOTOR HOSES FOR BLOCKAGE
- Disconnect: Vacuum Control Motors.
- Connect a vacuum pump to each hose and try to pull a vacuum. If the vacuum pump can pull and hold a vacuum, the hose is plugged. If the vacuum pump pulls a vacuum that slowly decays, the hose is restricted.
- Is the hose plugged or restricted?
Yes
REPAIR or INSTALL a new vacuum harness. TEST the system for normal operation.
No
GO to H15.
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H15 CHECK THE VACUUM CONTROL MOTOR INSTALLATION
- Check the attachment of the vacuum control motor arm to the damper door.
- Is the vacuum control motor arm attached to the door or door crank arm?
Yes
REPAIR the damper door. TEST the system for normal operation.
No
CONNECT the vacuum control motor arm to the door crank arm. TEST the system for normal operation.
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