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Diagnostic Procedure For Blower Motor

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

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

Fig 1: Blower Motor Circuit Diagram
G00867407Courtesy of NISSAN MOTOR CO., U.S.A.
  1. CHECK FUSES 

    Check 20A fuses [No. 28 and 30 (Located in the fuse and fusible link box)]. For fuse layout. Refer to FUSES & CIRCUIT BREAKERS - QUEST .

    Fuses are good. 

    OK or NG 

    1. OK: GO TO 2.
    2. NG: GO TO  10.
  2. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT 
    1. Disconnect front blower motor connector.
    2. Press the mode switch to select any mode except off.
    3. Set fan switch to high.
    4. Check voltage between front blower motor harness connector M62 terminal + (W/L) and ground.

      Battery voltage should exist. 

    OK or NG 

    1. OK: GO TO  12.
    2. NG: GO TO 3.
      Fig 2: Checking Voltage Between Front Blower Motor Harness Connector Terminal And Ground
      G00867408Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT 

    Check voltage between front blower motor relay harness connector H2 terminals 3 (L) and 6 (L/W) and ground.

    Battery voltage should exist. 

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Repair harness or connector.
      Fig 3: Checking Voltage Between Front Blower Motor Relay Harness Connector Terminal And Ground
      G00867409Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK FRONT BLOWER MOTOR RELAY 

    Refer to "FRONT BLOWER MOTOR RELAY ".

    OK or NG 

    1. OK: GO TO 5.
    2. NG: Replace front blower motor relay.
  5. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN 
    1. Disconnect blower motor relay harness connector and front blower motor harness connector.
    2. Check continuity between front blower motor relay harness connector H2 terminals 5 (W/L) and 7 (W/L) and front blower motor harness connector M62 terminal + (W/L).

      Continuity should exist. 

    OK or NG 

    1. OK: GO TO 6.
    2. NG: Repair harness or connector.
      Fig 4: Checking Continuity Between Front Blower Motor Relay Harness Connector Terminal And Front Blower Motor Harness Connector
      G00867410Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN 
    1. Disconnect variable blower control harness connector.
    2. Check continuity between front blower motor relay harness connector H2 terminals 5 (W/L) and 7 (W/L) and variable blower control harness connector M122 terminal 1 (W/L).

      Continuity should exist. 

    OK or NG 

    1. OK: GO TO 7.
    2. NG: Repair harness or connector.
      Fig 5: Checking Continuity Between Front Blower Motor Relay Harness Connector Terminal And Variable Connector
      G00867411Courtesy of NISSAN MOTOR CO., U.S.A.
  7. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT 
    1. Disconnect front air control connector.
    2. Check continuity between front air control connector M49 terminal 13 (O) and variable blower control connector M122 terminal 2 (O).

      Continuity should exist. 

    OK or NG 

    1. OK: GO TO 8.
    2. NG: Repair harness or connector.
      Fig 6: Checking Continuity Between Front Air Control Connector And Variable Blower Control Connector
      G00867412Courtesy of NISSAN MOTOR CO., U.S.A.
  8. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY 

    Check voltage between front blower motor relay connector H2 terminal 1 (G/Y) and ground.

    Battery voltage should exist. 

    OK or NG 

    1. OK: GO TO 9.
    2. NG: Repair harness or connector.
      Fig 7: Checking Voltage Between Front Blower Motor Relay Connector Terminal And Ground
      G00867413Courtesy of NISSAN MOTOR CO., U.S.A.
  9. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT 

    Check continuity between front blower motor relay connector H2 terminal 2 (G/B) and front air control harness connector M49 terminal 26 (G/B).

    Continuity should exist. 

    OK or NG 

    1. OK: Replace front air control. Refer to "FRONT AIR CONTROL ".
    2. NG: Repair harness or connector.
      Fig 8: Checking Continuity Between Front Blower Motor Relay Connector And Front Air Control Harness Connector
      G00867414Courtesy of NISSAN MOTOR CO., U.S.A.
  10. REPLACE FUSES 
    1. Replace fuses.
    2. Activate the front blower motor.
    3. Does fuse blow?

    OK or NG 

    1. Yes: GO TO 11.
    2. No: INSPECTION END.
  11. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT 
    1. Disconnect front blower motor harness connector.
    2. Check continuity between variable blower control harness connector M122 terminal 1 (W/L) and ground.

      Continuity should not exist. 

    OK or NG 

    1. OK: GO TO 12.
    2. NG: Repair harness or connector.
      Fig 9: Checking Continuity Between Variable Blower Control Harness Connector Terminal And Ground
      G00867415Courtesy of NISSAN MOTOR CO., U.S.A.
  12. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT 
    1. Disconnect front air control connector
    2. Check continuity between front air control connector M49 terminal 13 (O) and variable blower control connector M122 terminal 2 (O)

      Continuity should exist. 

    OK or NG 

    1. OK: Check blower motor, if OK replace variable blower control. Refer to "FRONT BLOWER MOTOR ".
    2. NG: Repair harness or connector.
      Fig 10: Checking Continuity Between Front Air Control Connector And Variable Blower Control Connector
      G00867416Courtesy of NISSAN MOTOR CO., U.S.A.
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