Blower Motor Circuit

SYMPTOM:

• Blower motor does not rotate. 

Fig 1: Blower Motor Circuit Symptom

Courtesy of NISSAN MOTOR CO., U.S.A.

1. DIAGNOSTIC PROCEDURE 

   Check if blower motor rotates properly at each fan speed.

   Conduct checks as per symptom table above.

   1. 1: GO TO   2 . 
   2. 2, 3, 4  : GO TO  8.
   3. 5  : GO TO  10
2. CHECK POWER SUPPLY FOR BLOWER MOTOR 
   1. Disconnect blower motor harness connector.
   2. Do approx. 12 volts exist between blower motor harness terminal + and body ground?
      Fig 2: Checking Power Supply For Blower Motor

      Courtesy of NISSAN MOTOR CO., U.S.A.

   Yes or No 

   1. Yes: GO TO 3.
   2. No: Check 15A (Nos. 14 and 16) fuses block. Refer to FUSES & CIRCUIT BREAKERS - SENTRA .
3. CHECK CIRCUIT CONTINUITY FOR BLOWER MOTOR 
   1. Turn fan control switch to any position except OFF.
   2. Check circuit continuity between blower motor connector M57 terminal - (L/B) and body ground.

      Continuity should exist. 

   OK or NG 

   1. OK: GO TO 4.
   2. NG: Reconnect blower motor harness connector. GO TO 5.
      Fig 3: Checking Circuit Continuity For Blower Motor

      Courtesy of NISSAN MOTOR CO., U.S.A.
4. CHECK BLOWER MOTOR 

   Refer to "BLOWER MOTOR ".

   OK or NG 

   1. OK: INSPECTION END. 
   2. NG: Replace blower motor.
5. CHECK BLOWER MOTOR CIRCUIT BETWEEN BLOWER MOTOR AND FAN RESISTOR 

   Do approx. 12 volts exist between fan resistor harness terminal No. 1 and body ground?

   Fig 4: Checking Blower Motor Circuit Between Blower Motor And Fan Resistor

   Courtesy of NISSAN MOTOR CO., U.S.A.

   Yes or No 

   1. Yes: Disconnect fan control switch harness connector. GO TO  7.
   2. No: Disconnect blower motor and fan resistor harness connectors. GO TO 6.
6. CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND FAN RESISTOR 

   Check circuit continuity between blower motor harness terminal - and fan resistor harness terminal No. 1.

   Fig 5: Checking Circuit Continuity Between Blower Motor And Fan Resistor

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   1. OK: Check harness for short and repair as necessary.
   2. NG: Check harness for open and check connectors. Repair as necessary.
7. CHECK GROUND CIRCUIT FOR FAN CONTROL SWITCH 

   Check circuit continuity between fan control switch harness terminal No. 5 and body ground.

   Fig 6: Checking Ground Circuit For Fan Control Switch

   Courtesy of NISSAN MOTOR CO., U.S.A.

   OK or NG 

   1. OK: GO TO 8.
   2. NG: Repair harness or connector.
8. CHECK RESISTOR AFTER DISCONNECTING IT 

   Refer to "FAN RESISTOR ".

   OK or NG 

   1. OK: GO TO 9.
   2. NG: Replace fan resistor.
9. CHECK FAN RESISTOR HARNESS CONNECTOR 

   Reconnect fan resistor harness connector.

   1. 1  : GO TO  12.
   2. 2, 3, 4  : GO TO 10.
10. CHECK FAN CONTROL SWITCH CIRCUIT 

    Do approx. 12 volts exist between each fan control switch harness terminal and body ground?

    Fig 7: Checking Fan Control Switch Circuit

    Courtesy of NISSAN MOTOR CO., U.S.A.

    Yes or No 

    1. Yes: GO TO  12.
    2. No: GO TO 11.
11. CHECK CIRCUIT CONTINUITY BETWEEN FAN CONTROL SWITCH AND FAN RESISTOR 

    Check circuit continuity between fan control switch harness terminal and fan resistor harness terminal.

    Fig 8: Checking Circuit Continuity Between Fan Control Switch And Fan Resistor

    Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: Check harness for short and repair as necessary.
    2. NG: Check harness for open and check connectors. Repair as necessary.
12. CHECK FAN CONTROL SWITCH AFTER DISCONNECTING IT 

    Refer to "FAN CONTROL SWITCH ".

    OK or NG 

    1. OK: INSPECTION END. 
    2. NG: Replace fan control switch.