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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.

Fig 1: Identifying Blower Motor Circuit Diagram
G00848901Courtesy of NISSAN MOTOR CO., U.S.A.
  1. DIAGNOSTIC PROCEDURE 

    Turn the front blower switch to each of its four speeds. Does blower motor rotate normally at each speed?

    OK or NG 

    1. OK: INSPECTION END.
    2. NG :
      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 

    Check 20A fuses [Nos. 28 and 30, located in the fuse and fusible link box]. Refer to "FUSES & CIRCUIT BREAKERS - QUEST ".

    OK or NG 

    1. OK: GO TO 3.
    2. NG: GO TO  8.
  3. CHECK FRONT BLOWER MOTOR POWER SUPPLY 
    1. Disconnect front blower motor harness connector.
    2. Select any front blower speed except OFF.
    3. 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  11.
      2. NG: GO TO 4.
        Fig 2: Check Voltage Between Front Blower Motor Harness Connector M62 Terminal + (W/L) And Ground
        G00867408Courtesy 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 POWER FROM RELAY TO FRONT BLOWER MOTOR 
    1. Reconnect front blower motor harness connector.
    2. Disconnect front blower motor relay.
    3. Connect a jumper wire between front blower motor relay connector H2 (harness side) terminals 3 and 5 and between front blower motor relay connector H2 (harness side) terminals 6 and 7.
    4. Momentarily (no more than 4 seconds), set front blower switch to any position except OFF.

      Front blower motor should rotate. 

      OK or NG 

      1. OK: GO TO 6.
      2. NG: GO TO  10.
        Fig 3: Connecting A Jumper Wire Between Front Blower Motor Relay Connector H2 Terminals 3 And 5 And Between Front Blower Motor Relay Connector H2 Terminals 6 And 7
        G00848903Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY CIRCUIT 
    1. Turn ignition key ON,
    2. Set front blower switch to any position except OFF.
    3. Check voltage between front blower motor relay harness connector H2 terminal 1 (G/Y) and ground.

      Battery voltage should exist. 

      OK or NG 

      1. OK: GO TO 7.
      2. NG: Repair harness or connector.
        Fig 4: Checking Voltage Between Front Blower Motor Relay Harness Connector H2 Terminal 1 (G/Y) And Ground
        G00848904Courtesy of NISSAN MOTOR CO., U.S.A.
  7. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT 

    Check continuity between front blower motor relay harness connector H2 terminal 2 (B) and ground. Continuity should exist.

    OK or NG 

    1. OK: Replace front blower motor relay.
    2. NG: Repair harness or connector.
      Fig 5: Checking Continuity Between Front Blower Motor Relay Harness Connector H2 Terminal 2 (B) And Ground
      G00848905Courtesy of NISSAN MOTOR CO., U.S.A.
  8. REPLACE FUSE 

    Refer to "FUSES & CIRCUIT BREAKERS - QUEST ".

    Does fuse open when front blower motor is turned on?

    YES or NO 

    1. Yes: GO TO 9.
    2. No: INSPECTION END.
  9. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT 
    1. Disconnect front blower motor harness connector.
    2. Check continuity between front blower motor harness connector M62 terminal + (W/L) and ground.

      Continuity should not exist. 

      OK or NG 

      1. OK: Check front blower motor. Refer to "FRONT BLOWER MOTOR ".
      2. NG: Repair harness or connector.
        Fig 6: Checking Continuity Between Front Blower Motor Harness Connector M62 Terminal + (W/L) And Ground
        G00848906Courtesy of NISSAN MOTOR CO., U.S.A.
  10. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT 
    1. Disconnect front blower motor harness connector.
    2. Check continuity between front blower motor relay harness connector H2 terminal 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: Repair harness or connector between front blower motor fuses and front blower motor relay.
      2. NG: Repair harness or connector between front blower motor relay and front blower motor.
        Fig 7: Check Continuity Between Front Blower Motor Relay Harness Connector H2 Terminal 5 (W/L) And 7 (W/L) And Front Blower Motor Harness Connector M62 Terminal + (W/L)
        G00848907Courtesy of NISSAN MOTOR CO., U.S.A.
  11. CHECK FRONT BLOWER MOTOR 

    Refer to "FRONT BLOWER MOTOR ".

    OK or NG 

    1. OK: GO TO 12.
    2. NG: Replace front blower motor.
  12. CHECK FRONT BLOWER SWITCH 

    Refer to "FRONT BLOWER SWITCH ".

    OK or NG 

    1. OK: Repair harness or connector between front blower switch and front blower motor.
    2. NG: Replace front air control. Refer to "FRONT AIR CONTROL ".
  13. CHECK FRONT BLOWER MOTOR RESISTOR 

    Refer to "FRONT BLOWER MOTOR RESISTOR ".

    OK or NG 

    1. OK: GO TO 14.
    2. NG: Replace front blower motor resistor. Refer to "REMOVAL AND INSTALLATION ".
  14. CHECK FRONT BLOWER SWITCH CIRCUIT 
    1. Reconnect front blower motor resistor harness connector.
    2. Check voltage between front blower switch connector M51 terminals 2 (G/B), 3 (L/Y), and 7 (L/R) and ground.
      Fig 8: Front Blower Switch Connector M51 Terminals 2, 3 And 7 Voltage Specifications
      G00848908Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 9: Checking Voltage Between Front Blower Switch Connector M51 Terminals 2 (G/B), 3 (L/Y), And 7 (L/R) And Ground
      G00848909Courtesy of NISSAN MOTOR CO., U.S.A.

      OK or NG 

      1. OK: Replace front air control. Refer to "FRONT AIR CONTROL ".
      2. NG: GO TO 15.
  15. CHECK FRONT BLOWER MOTOR GROUND CIRCUIT TO FRONT BLOWER MOTOR RESISTOR 
    1. Disconnect front blower motor and front blower motor resistor harness connector.
    2. Check continuity between front blower motor connector M62 terminal - (LAN) and front blower motor resistor harness connector M122 terminal 3 (L/W).

      Continuity should exist. 

    3. Check continuity between front blower motor connector M62 terminal - (L/W) and ground.

      Continuity should not exist. 

      OK or NG 

      1. OK : INSPECTION END.
      2. NG: Repair harness or connector.
        Fig 10: Checking Front Blower Motor Ground Circuit To Front Blower Motor Resistor
        G00848910Courtesy of NISSAN MOTOR CO., U.S.A.
  16. CHECK FRONT BLOWER SWITCH 

    Refer to "FRONT BLOWER SWITCH ".

    OK or NG 

    1. OK: Repair harness or connector.
    2. NG: Replace front air control. Refer to "FRONT AIR CONTROL ".
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