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Diagnostic Procedure For Blower Motor

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: Blower motor operation is malfunctioning under starting blower speed control.

Fig 1: Identifying Blower Motor Circuit Diagram
G04896242
  1. DIAGNOSTIC PROCEDURE 
    1. Turn ignition switch ON.
    2. Turn the front blower switch to each of its four speeds.

    Does blower motor rotate normally at each speed?

    Yes or No 

    YES: Inspection End.

    NO:

    1. Does not rotate at any speed, GO TO 2.
    2. Does not rotate at 1 - 3 speed, GO TO  13.
    3. Does not rotate at 4 speed, GO TO  16.
  2. CHECK FUSES 
    1. Check 15A fuses (Nos. 24 and 27, located in the fuse and fusible link box). Refer to "FUSE AND FUSIBLE LINK BOX ".
    2. Check 10A fuse [No. 8, located in the fuse block (JB)]. Refer to "FUSE BLOCK-JUNCTION BOX (J/B) ".

    OK or NG 

    OK: GO TO 3.

    NG: GO TO  8.

  3. CHECK FRONT BLOWER MOTOR POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect front blower motor harness connector.
    3. Turn ignition switch ON.
    4. Select any front blower speed except OFF.
    5. Check voltage between front blower motor harness connector M62 terminal 2 and ground.

      2 - Ground : Battery voltage 

      Fig 2: Checking Voltage Between Front Blower Motor Connector M62 Terminal 2 And Ground
      G04903356

    OK or NG 

    OK: GO TO  12.

    NG: GO TO 4.

  4. CHECK FRONT BLOWER MOTOR RELAY 
    1. Turn Ignition switch OFF.
    2. Check front blower motor relay. Refer to "FRONT BLOWER MOTOR RELAY ".

    OK or NG 

    OK: GO TO 5.

    NG: Replace front blower motor relay.

  5. CHECK FRONT BLOWER MOTOR RELAY POWER SUPPLY (SWITCH SIDE) 

    Check voltage between front blower motor relay harness connector E54 terminals 7 and 5 and ground.

    TERMINALS VOLTAGE REFERENCE

    A Condition Voltage (Approx.)
    (+)  
    Front air control connector Terminal (-)    
    M54 5 Ground Blower motor relay power supply Battery voltage
    M54 7 Ground Blower motor relay power supply Battery voltage
    Fig 3: Checking Voltage Between Front Blower Motor Relay Connector E54 Terminals 7 And 5 And Ground
    G04913637

    OK or NG 

    OK: GO TO 6.

    NG: Repair harness or connector.

  6. CHECK FRONT BLOWER MOTOR RELAY POWER SUPPLY (COIL SIDE) 
    1. Turn ignition switch ON.
    2. Check voltage between front blower motor relay harness connector E54 terminal 1 and ground.
      TERMINALS VOLTAGE REFERENCE

      A Condition Voltage (Approx.)
      (+)  
      Front air control connector Terminal (-)    
      M54 1 Ground Blower motor relay power supply (coil side) Battery voltage
      Fig 4: Checking Voltage Between Front Blower Motor Relay Connector E54 Terminal 1 And Ground
      G04913638

    OK or NG 

    OK: GO TO 7.

    NG: Repair or replace harness as necessary.

  7. CHECK FRONT BLOWER MOTOR POWER FROM RELAY TO FRONT BLOWER MOTOR 
    1. Turn ignition switch OFF.
    2. Check continuity between front blower motor relay harness connector E54 terminals 6 and 3 and front blower motor harness connector M62 terminal 2.

      3, 6 - 2 : Continuity should exist. 

      Fig 5: Checking Continuity Between Front Blower Motor Relay Terminals And Front Blower Motor Terminal
      G04896246

    OK or NG 

    OK: Repair or replace harness as necessary.

    NG: Repair harness or connector between the front blower motor relay and the front blower motor.

  8. REPLACE FUSE 

    Refer to "FUSE AND FUSIBLE LINK BOX ".

    Does fuse No. 24 or 27 open when the front blower motor is turned on?

    Yes or No 

    YES: GO TO  10.

    NO: GO TO 9.

  9. REPLACE FUSE 

    Refer to "FUSE BLOCK-JUNCTION BOX (J/B) ".

    Does fuse No. 8 open when the ignition switch is turned ON?

    Yes or No 

    YES: Repair or replace harness as necessary.

    NO: Inspection End.

  10. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect front blower motor connector.
    3. Check continuity between front blower motor harness connector M62 terminal 2 and ground.

      2 - Ground : Continuity should not exist. 

      Fig 6: Checking Continuity Between Front Blower Motor Connector M62 Terminal 2 And Ground
      G04896247

    OK or NG 

    OK: GO TO 11.

    NG: Repair or replace harness as necessary.

  11. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT FOR SHORT 
    1. Disconnect front blower motor relay connector.
    2. Check continuity between the front blower motor relay harness connector E54 terminal 7 and terminal 5 and ground.

      7, 5 - Ground : Continuity should not exist. 

      Fig 7: Checking Continuity Between Front Blower Motor Relay Connector E54 Terminal 7 And Ground
      G04896248

    OK or NG 

    OK: Check front blower motor. Refer to "FRONT BLOWER MOTOR ".

    NG: Repair harness or connector.

  12. CHECK FRONT BLOWER MOTOR 
    1. Turn ignition switch OFF.
    2. Check front blower motor. Refer to "FRONT BLOWER MOTOR ".

    OK or NG 

    OK: GO TO 13.

    NG: Replace front blower motor. Refer to "BLOWER MOTOR ".

  13. CHECK FRONT BLOWER MOTOR RESISTOR 

    Check front blower motor resistor. Refer to "BLOWER MOTOR RESISTOR ".

    OK or NG 

    OK: GO TO 14.

    NG: Replace front blower motor resistor. Refer to "REMOVAL AND INSTALLATION ".

  14. CHECK FRONT BLOWER SWITCH 

    Check front blower switch. Refer to "FRONT BLOWER SWITCH ".

    OK or NG 

    OK: GO TO 15.

    NG: Replace front blower switch. Refer to "FRONT AIR CONTROL ".

  15. CHECK FRONT BLOWER MOTOR GROUND CIRCUIT TO FRONT BLOWER MOTOR RESISTOR 
    1. Disconnect front blower motor resistor harness connector.
    2. Check continuity between front blower motor connector M62 (A) terminal 1 and front blower motor resistor harness connector M122 (B) terminal 3.
      TERMINALS CONTINUITY REFERENCE

      A B  
      Connector Terminal Connector Terminal Continuity
      Front blower motor: M62 1 Front blower motor resistor: M122 3 Yes
      3. Fig 8: Checking Continuity Between Front Blower Motor Terminal 1 And Front Blower Motor Resistor Terminal 3
      G04913642

    OK or NG 

    OK: Repair harness or connector between front blower switch connector M51 terminal 8 and ground.

    NG: Repair harness or connector between front blower motor resistor and front blower motor.

  16. CHECK FRONT BLOWER SWITCH 

    Check front blower switch. Refer to "FRONT BLOWER SWITCH ".

    OK or NG 

    OK: Repair harness or connector between front blower motor switch connector M51 terminal 8 and front blower motor resistor connector M122 terminal 3.

    NG: Replace front blower switch. Refer to "FRONT AIR CONTROL ".

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