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Home >> Infiniti >> 2004 >> QX56 RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1228 (Automatic Air Conditioner) >> Trouble Diagnosis >> Rear Blower Motor Circuit >> Diagnostic Procedure For Rear Blower Motor >> Inspection Flow

Inspection Flow

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.
Fig 1: Rear Blower Motor Circuit - Inspection Flow Chart
G02385594Courtesy of NISSAN MOTOR CO., U.S.A.
  1. DIAGNOSTIC PROCEDURE 

    Blower motor rotates normally at each speed.

    OK or NG

    • OK: Inspection End.
    • 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 18.
  2. CHECK FUSES 

    Check 15A fuses [Nos. 10 and 11, located in the fuse block (J/B)]. Refer to "FUSE BLOCK-JUNCTION BOX (J/B) ".

    OK or NG

    • OK: GO TO 3.
    • NG: GO TO 8.
  3. CHECK REAR BLOWER MOTOR POWER SUPPLY 
    1. Turn ignition switch OFF.
    2. Disconnect rear blower motor connector.
    3. Select any rear blower speed except OFF.
    4. Turn ignition switch ON.
    5. Check voltage between rear blower motor harness connector B134 terminal 2 (L/R) and ground.
      • 2 - Ground: Battery voltage. 

    OK or NG

    • OK: GO TO 11.
    • NG: GO TO 4.
    Fig 2: Checking Voltage Between Rear Blower Motor Harness Connector B134 Terminal 2 (L/R) And Ground
    G02385595Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK REAR BLOWER MOTOR RELAY 

    Turn ignition switch OFF.

    Refer to "REAR BLOWER MOTOR RELAY ".

    OK or NG

    • OK: GO TO 5.
    • NG: Replace rear blower motor relay.
  5. CHECK REAR BLOWER MOTOR POWER FROM RELAY TO REAR BLOWER MOTOR 
    1. Reconnect rear blower motor connector.
    2. Disconnect rear blower motor relay J-1.
    3. Turn ignition switch ON.
    4. Set rear blower switch (front) to any position except OFF, REAR, or 4 - speed.
    5. Momentarily (no more than 4 seconds), connect a jumper wire between rear blower motor relay connector J-1 (harness side) terminals 3 and 5.
      • Rear blower motor should rotate. 

    OK or NG

    • OK: GO TO 6.
    • NG: GO TO 10.
    Fig 3: Connecting Jumper Wire Between Rear Blower Motor Relay Connector J-1 (Harness Side) Terminals 3 And 5
    G02385596Courtesy of NISSAN MOTOR CO., U.S.A.
  6. CHECK REAR BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect fuse block (J/B) connector.
    3. Turn ignition switch ON.
    4. Set rear blower switch (front) to any position except OFF, REAR, or 4 - speed.
    5. Check voltage between fuse block (J/B) harness connector M39 terminal 3Q (W/L) and ground.
      • 3Q - Ground: Battery voltage. 

    OK or NG

    • OK: GO TO 7.
    • NG: GO TO 20.
    Fig 4: Checking Voltage Between Fuse Block (J/B) Harness Connector M39 Terminal 3Q (W/L) And Ground
    G02385597Courtesy of NISSAN MOTOR CO., U.S.A.
  7. CHECK REAR BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT 
    1. Turn ignition switch OFF.
    2. Check continuity between fuse block (J/B) harness connector M3 terminal 7N (B) and ground.
      • 7N - Ground: Continuity should exist. 

    OK or NG

    • OK: Replace fuse block (J/B).
    • NG: Repair harness or connector.
    Fig 5: Checking Continuity Between Fuse Block (J/B) Harness Connector M3 Terminal 7N (B) And Ground
    G02385598Courtesy of NISSAN MOTOR CO., U.S.A.
  8. REPLACE FUSE 

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

    Fuse should not open when rear blower motor is activated.

    OK or NG

    • OK: Inspection End.
    • NG: GO TO 9.
  9. CHECK REAR BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect battery cables and rear blower motor connector.
    3. Check continuity between rear blower motor harness connector B134 terminal 2 (L/R) and ground.
      • 2 - Ground: Continuity should not exist. 

    OK or NG

    Fig 6: Checking Continuity Between Rear Blower Motor Harness Connector B134 Terminal 2 (L/R) And Ground
    G02385599Courtesy of NISSAN MOTOR CO., U.S.A.
  10. CHECK REAR BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect fuse block (J/B) and rear blower motor connectors.
    3. Check continuity between fuse block (J/B) harness connector M3 terminal 3N (SB) and 8N (L/R) and rear blower motor harness connector B134 terminal 2 (L/R).
      • 3N, 8N - 2: Continuity should exist. 

    OK or NG

    • OK: GO TO 20.
    • NG: Repair harness or connector.
    Fig 7: Checking Continuity Between Fuse Block (J/B) Harness Connector M3 Terminal 3N, 8N And Rear Blower Motor Harness Connector B134 Terminal 2
    G02385600Courtesy of NISSAN MOTOR CO., U.S.A.
  11. CHECK REAR BLOWER MOTOR 

    Refer to "FRONT BLOWER MOTOR ".

    OK or NG

  12. CHECK REAR BLOWER SWITCH (FRONT) 

    Refer to "REAR BLOWER SWITCH (FRONT) ".

    OK or NG

    • OK: GO TO 15.
    • NG: Replace rear blower switch (front). Refer to "FRONT AIR CONTROL ".
  13. CHECK REAR BLOWER MOTOR RESISTOR 

    Refer to "REAR BLOWER MOTOR RESISTOR ".

    OK or NG

  14. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect rear blower switch (front) M52.
    3. Turn ignition switch ON.
    4. Reconnect rear blower motor resistor harness connector B133.
    5. Check voltage between each rear blower switch (front) connector M52 terminals 3 (LG), 7 (W/L), and 8 (G), and ground.
      Fig 8: Rear Blower Switch (Front) Connector Terminals And Ground Voltage Specifications
      G02385601Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 9: Checking Voltage Between Each Rear Blower Switch (Front) Connector M52 Terminals 3, 7, 8 And Ground
      G02385602Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO 17.
    • NG: GO TO 16.
  15. CHECK REAR BLOWER MOTOR GROUND CIRCUIT TO REAR BLOWER MOTOR RESISTOR 
    1. Turn ignition switch OFF.
    2. Disconnect rear blower motor and rear blower motor resistor connectors.
    3. Check continuity between rear blower motor connector B134 terminal 1 (L/B) and rear blower motor resistor harness connector B133 terminal 3 (L/B).
      • 1-3: Continuity should exist. 
    4. Check continuity between rear blower motor connector B134 terminal 1 (L/B) and ground.
      • 1 - Ground: Continuity should not exist. 

    OK or NG

    • OK: GO TO 16.
    • NG: Repair harness or connector.
    Fig 10: Checking Continuity Between Rear Blower Motor Connector B134 Terminal 1 And Rear Blower Motor Resistor Harness Connector B133 Terminal 3
    G02385603Courtesy of NISSAN MOTOR CO., U.S.A.
  16. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect rear blower motor resistor connector.
    3. Check continuity between rear blower switch (front) connector M52 terminals 3 (LG), 7 (W/L), and 8 (G), and rear blower motor resistor connector B133 terminals 1 (LG), 4 (W/L), and 2 (G).
      Fig 11: Rear Blower Switch (Front) Connector M52 Terminals And Rear Blower Motor Resistor Connector B133 Terminals Continuity Chart
      G02385604Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 12: Checking Continuity Between Rear Blower Switch (Front) Connector M52 Terminals 3, 7, 8 And Rear Blower Motor Resistor Connector B133 Terminals 1 , 4 And 2
      G02385605Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: Inspection End.
    • NG: Repair harness or connector.
  17. CHECK REAR BLOWER SWITCH (FRONT) CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect rear blower switch (rear) connectors.
    3. Check continuity between rear blower switch (front) connector M52 terminals 3 (LG), 5 (L/B), 7 (W/L), and 8 (G), and rear blower switch (rear) connector R208 terminals 9 (LG), 6 (L/B), 8 (W/L), and 7 (G).
      Fig 13: Rear Blower Switch (Front) Connector M52 Terminals And Rear Blower Switch (Rear) Connector R208 Terminals Continuity Chart
      G02385606Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 14: Checking Continuity Between Rear Blower Switch (Front) Connector M52 Terminals 3, 5, 7, 8 And Rear Blower Switch (Rear) Connector R208 Terminals 9, 6, 8 And 7
      G02385607Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: GO TO 18.
    • NG: Repair harness or connector.
  18. CHECK REAR BLOWER SWITCH (FRONT) 

    Refer to "REAR BLOWER SWITCH (FRONT) ".

    OK or NG

    • OK: GO TO 19.
    • NG: Replace rear blower switch (front). Refer to "FRONT AIR CONTROL ".
  19. CHECK REAR BLOWER SWITCH (REAR) 

    Refer to "REAR BLOWER SWITCH (REAR) ".

    OK or NG

    • OK: Inspection End.
    • NG: Replace rear blower switch (rear). Refer to "REAR AIR CONTROL ".
  20. CHECK CIRCUIT BETWEEN FRONT AIR CONTROL AND FUSE BLOCK (J/B) [REAR BLOWER MOTOR RELAY (COIL SIDE) POWER] 
    1. Disconnect front air control and fuse block (J/B) connectors M39.
    2. Check continuity between front air control harness connector M50 terminal 38 (W/L) and fuse block (J/B) connector M39 terminal 3Q (W/L).
      • Continuity should exist. 

    OK or NG

    • OK: Replace front air control. Refer to "FRONT AIR CONTROL ".
    • NG: Repair harness or connector.
    Fig 15: Checking Continuity Between Front Air Control Harness Connector M50 Terminal 38 And Fuse Block (J/B) Connector M39 Terminal 3Q
    G02385608Courtesy of NISSAN MOTOR CO., U.S.A.
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