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Diagnostic Procedure For Blower Motor

WARNING: This page is about a different car, the 2008 Nissan Maxima. 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: Diagnostic Procedure For Blower Motor
G04917576Courtesy of NISSAN MOTOR CO., U.S.A.
  1. CHECK POWER SUPPLY FOR BLOWER MOTOR 
    1. Disconnect blower motor harness connector.
    2. Turn ignition switch ON.
    3. Check voltage between blower motor harness connector M62 terminal 1 and ground.
      POWER SUPPLY FOR BLOWER MOTOR

      Terminal Voltage (V) (Approx.)
      (+) (-)
      Connector - Terminal Body ground 12V
      M62-1
    Fig 2: Checking Voltage Between Blower Motor Harness Connector M62 Terminal 1 And Ground
    G04917577Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  2.

    NG: Check power supply circuit and 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)].

    • Check blower motor relay. Refer to "IGNITION POWER SUPPLY - IGNITION SW. IN ON "
    • If OK, check for open circuit in wiring harness.

      Repair or replace as necessary.

    • If OK, replace fuse and check wiring harness for short circuit.

      Repair or replace as necessary.

  2. CHECK BLOWER MOTOR 

    Check blower motor. Refer to "FRONT BLOWER MOTOR ".

    OK or NG 

    OK: GO TO  3.

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

  3. CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND FAN CONTROL AMP  .
    1. Turn ignition switch OFF.
    2. Disconnect fan control amp.
    3. Check continuity between blower motor harness connector M62 terminal 2 and fan control amp. harness connector M64 terminal 3.
      CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND FAN CONTROL AMP

      Terminals Continuity
      Connector - Terminal Connector
      M62-2 M64-3 Yes
      Fig 3: Checking Continuity Between Blower Motor Connector M62 Terminal 2 And Fan Control Amp. Connector M64 Terminal 3
      G04917578Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  4.

    NG: Repair harness or connector.

  4. CHECK VOLTAGE FOR FAN CONTROL AMP  .
    1. Turn ignition switch ON.
    2. Press fan switch to any position except OFF or AUTO.
    3. Check voltage between fan control amp. harness connector M64 terminal 2 and ground.
      VOLTAGE FOR FAN CONTROL AMP

      Terminals Voltage (V) (Approx.)
      (+) (-)
      Connector - Terminal Body ground
      M64-2 12V
    Fig 4: Checking Voltage Between Fan Control Amp. Harness Connector M64 Terminal 2 And Ground
    G04917579Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  5.

    NG: GO TO  7.

  5. CHECK CIRCUIT CONTINUITY BETWEEN UNIFIED METER AND A/C AMP. AND FAN CONTROL AMP  .
    1. Turn ignition switch OFF.
    2. Disconnect unified meter and A/C amp.
    3. Check continuity between unified meter and A/C amp. harness connector M89 (A) terminal 47 and fan control amp. harness connector M64 (B) terminal 3.
      CIRCUIT CONTINUITY BETWEEN UNIFIED METER AND A/C AMP. AND FAN CONTROL AMP

      Terminals Continuity
      Connector - Terminal Connector
      M89-47 M64-3 Yes
      Fig 5: Checking Continuity Between Unified Meter And A/C Amp. And Fan Control Amp. Connector Terminal
      G04917580Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO  6.

    NG: Repair harness or connector.

  6. CHECK BODY GROUND CIRCUIT FOR FAN CONTROL AMP  .

    Check continuity between fan control amp. harness connector M64 terminal 1 and ground.

    BODY GROUND CIRCUIT FOR FAN CONTROL AMP

    Terminals Continuity
    Connector - Terminal Body ground Yes
    M64-1
    Fig 6: Checking Continuity Between Fan Control Amp. Harness Connector M64 Terminal 1 And Ground
    G04917581Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK:

    1. Replace fan control amp. Refer to "FAN CONTROL AMPLIFIER ".
    2. Confirm that blower motor operation is normal.

    NG: Repair harness or connector.

  7. CHECK FAN CONTROL AMP. CIRCUIT BETWEEN FAN CONTROL AMP. AND UNIFIED METER AND A/C AMP  .
    1. Turn ignition switch OFF.
    2. Disconnect unified meter and A/C amp. connector.
    3. Check continuity between fan control amp. harness connector M64 terminal 2 and unified meter and A/C amp. harness connector M89 terminal 60.
      FAN CONTROL AMP. CIRCUIT BETWEEN FAN CONTROL AMP. AND UNIFIED METER AND A/C AMP

      Terminals Continuity
      Connector - Terminal Connector Yes
      M64-2 M89-60

    If OK, check harness for short.

    Fig 7: Checking Fan Control Amp. Between Fan Control Amp. And Unified Meter And A/C Amp. Connector Terminal
    G04917582Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK:

    1. Replace unified meter and A/C amp. Refer to "REMOVAL AND INSTALLATION ".
    2. Confirm that blower motor operation is normal.

    NG: Repair harness or connector.

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