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Diagnostic Procedure For Blower Motor

WARNING: This page is about a different car, the 2005 Infiniti QX56. 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: Diagnostic Procedure For Blower Motor
G02385577Courtesy of NISSAN MOTOR CO., U.S.A.
  1. CHECK FUSES 

    Check 20A fuses [No. 24 and 27 (Located in the fuse and fusible link box)]. For fuse layout. Refer to "FUSE AND FUSIBLE LINK BOX ".

    Fuses are good. 

    OK or NG

    • OK: GO TO 2.
    • NG: GO TO 10.
  2. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect front blower motor connector.
    3. Press the mode switch to select any mode except off.
    4. Turn the front blower control dial to high.
    5. Check voltage between front blower motor harness connector M62 terminal 2 (W/L) and ground.
      • 2 - Ground: Battery voltage. 

    OK or NG

    • OK: GO TO 12.
    • NG: GO TO 3.
    Fig 2: Checking Voltage Between Front Blower Motor Harness Connector M62 Terminal 2 (W/L) And Ground
    G02385578Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect front blower motor relay.
    3. Turn ignition switch ON.
    4. Check voltage between front blower motor relay harness connector M107 terminals 5 (G/R) and ground.
      • 5 - Ground: Battery voltage. 

    OK or NG

    • OK: GO TO 4.
    • NG: Repair harness or connector.
    Fig 3: Checking Voltage Between Front Blower Motor Relay Harness Connector M107 Terminal 5 And Ground
    G02385583Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK FRONT BLOWER MOTOR RELAY 

    Turn ignition switch OFF.

    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 (SWITCH SIDE) CIRCUIT FOR OPEN 

    Check continuity between front blower motor relay harness connector M107 terminal 3 (W/L) and front blower motor harness connector M62 terminal 2 (W/L).

    • 3 - 2: Continuity should exist. 

    OK or NG

    • OK: GO TO 6.
    • NG: Repair harness or connector.
    Fig 4: Checking Continuity Between Front Blower Motor Relay Harness Connector M107 Terminal 3 And Front Blower Motor Harness Connector M62 Terminal 2
    G02385579Courtesy 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 M107 terminals 3 (W/L) and variable blower control harness connector M122 terminal 1 (W/L).
      • 3 - 1: Continuity should exist. 

    OK or NG

    • OK: GO TO 7.
    • NG: Repair harness or connector.
    Fig 5: Checking Continuity Between Front Blower Motor Relay Harness Connector M107 Terminals 3 And Variable Blower Control Harness Connector M122 Terminal 1
    G02385580Courtesy 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 harness connector M49 terminal 13 (G/R) and variable blower control harness connector M122 terminal 2 (G/R).
      • 13 - 2: Continuity should exist. 

    OK or NG

    • OK: GO TO 8.
    • NG: Repair harness or connector.
    Fig 6: Checking Continuity Between Front Air Control Harness Connector M49 Terminal 13 And Variable Blower Control Harness Connector M122 Terminal 2
    G02385581Courtesy of NISSAN MOTOR CO., U.S.A.
  8. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY 
    1. Turn ignition switch ON.
    2. Check voltage between front blower motor relay harness connector M107 terminal 2 (Y/G) and ground.
      • 2 - Ground: Battery voltage. 

    OK or NG

    • OK: GO TO 9.
    • NG: Repair harness or connector.
    Fig 7: Checking Voltage Between Front Blower Motor Relay Harness Connector M107 Terminal 2 (Y/G) And Ground
    G02385582Courtesy of NISSAN MOTOR CO., U.S.A.
  9. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Check continuity between front blower motor relay connector M107 terminal 1 (R/B) and front air control harness connector M49 terminal 26 (R/B).
      • 1-26: Continuity should exist. 

    OK or NG

    • OK: Replace front air control. Refer to "FRONT AIR CONTROL ".
    • NG: Repair harness or connector.
    Fig 8: Checking Continuity Between Front Blower Motor Relay Connector M107 Terminal 1 And Front Air Control Harness Connector M49 Terminal 26
    G02385584Courtesy of NISSAN MOTOR CO., U.S.A.
  10. REPLACE FUSES 
    1. Replace fuses.
    2. Activate the front blower motor.
    3. Do fuses blow?

    YES or NO 

    • YES: GO TO 11.
    • NO: Inspection End.
  11. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect front blower motor connector and variable blower control connector.
    3. Check continuity between variable blower control harness connector M122 terminal 1 (W/L) and ground.
      • 1 - Ground.: Continuity should not exist. 

    OK or NG

    • OK: GO TO 12.
    • NG: Repair harness or connector.
    Fig 9: Checking Continuity Between Variable Blower Control Harness Connector M122 Terminal 1 (W/L) And Ground
    G02385585Courtesy 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 harness connector M49 terminal 13 (G/R) and variable blower control harness connector M122 terminal 2 (G/R).
      • 13 - 2: Continuity should exist. 

    OK or NG

    • OK: GO TO 13.
    • NG: Repair harness or connector.
    Fig 10: Checking Continuity Between Front Air Control Harness Connector M49 Terminal 13 And Variable Blower Control Harness Connector M122 Terminal 2
    G02385586Courtesy of NISSAN MOTOR CO., U.S.A.
  13. CHECK FRONT BLOWER MOTOR 

    Refer to "FRONT BLOWER MOTOR RELAY ".

    OK or NG

    • OK: GO TO 14.
    • NG: Replace front blower motor.
  14. CHECK BLOWER MOTOR GROUND CIRCUIT 

    Check continuity between front blower motor harness connector M62 terminal 1 (L/W) and variable blower control harness connector M122 terminal 3 (L/W).

    • 1-3: Continuity should exist. 

    OK or NG

    • OK: GO TO 15.
    • NG: Repair harness or connector.
    Fig 11: Checking Continuity Between Front Blower Motor Harness Connector M62 Terminal 1 And Variable Blower Control Harness Connector M122 Terminal 3
    G02385587Courtesy of NISSAN MOTOR CO., U.S.A.
  15. CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT 

    Check continuity between variable blower control harness connector M122 terminal 4 (B/W) and ground.

    • 4 - ground: Continuity should exist. 

    OK or NG

    Fig 12: Checking Continuity Between Variable Blower Control Harness Connector M122 Terminal 4 (B/W) And Ground
    G02385588Courtesy of NISSAN MOTOR CO., U.S.A.
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