INSPECTION PROCEDURE 3: The blower air volume cannot be changed


COMMENTS ON TROUBLE SYMPTOM
If the blower air volume is not changed by operating the blower switch, the blower switch may be defective.

PROBABLE CAUSES

  • Malfunction of the heater resistor
  • Malfunction of the blower switch
  • Damaged wiring harness or connector

DIAGNOSIS PROCEDURE

STEP 1. Check the heater resistor.
Refer to .

Q. Is the heater resistor in good condition?
Go to Step 2.
Replace the heater resistor.

STEP 2. Check open circuit in heater resistor line between blower motor connector and heater resistor connector.

Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. Resistance measurement at the blower switch connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Continuity between terminal 4 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Go to Step 4.

STEP 4. Check the blower switch.
Refer to .

Q. Is the blower switch in good condition?
Go to Step 5.
Replace the heater control panel.

STEP 5. Check open circuit in blower switch line between blower motor connector, heater resistor connector blower switch connector, and body earth.
note Before the wiring harness check, check the junction block connector and joint connector.

Q. Is the check result normal?
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
Repair the connector(s) or wiring harness.