INSPECTION PROCEDURE 3: The blower air volume cannot be changed
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COMMENTS ON TROUBLE SYMPTOM
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If the blower air volume is not changed by operating the blower switch, the blower switch may be defective.
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- Malfunction of the A/C temperature control resistor
- Malfunction of the blower switch
- Damaged wiring harness or connector
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STEP 1. Check the A/C temperature control resistor.
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Refer to  .
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Q.
Is the A/C temperature control resistor in good condition?
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 Go to Step 2.
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 Replace the A/C temperature control resistor (Refer to ).
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STEP 2. Voltage measurement at A/C temperature control resistor connector.
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Turn the ignition switch to the "ON" position.
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(3)Voltage between terminal 4 and body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 4.
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Go to Step 3.
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STEP 3. Check open circuit in A/C temperature control resistor line between blower motor connector and heater resister connector.
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Repair or replace the connector(s) or wiring harness.
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STEP 4. Check the blower switch.
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Refer to .
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Q.
Is the blower switch in good condition?
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Go to Step 5.
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Replace the heater controller assembly (Refer to ).
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STEP 5. Voltage measurement at blower switch connector.
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Turn the ignition switch to the "ON" position.
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(3)Voltage between terminal 1, 2, 4 and body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 7.
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Go to Step 6.
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STEP 6. Check open circuit in blower switch line between A/C temperature control resistor connector and blower switch connector.
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Repair or replace the connector(s) or wiring harness.
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STEP 7. Resistance measurement at the blower switch connector.
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Continuity between terminal 3 and body earth
OK: Continuity exists (2 Ω or less)
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Go to Step 8.
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STEP 8. Check open circuit in blower switch line between blower switch connector and body earth.
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
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Repair or replace the connector(s) or wiring harness.
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