Diagnostic Procedure

WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM:

Blower motor operation is malfunctioning.

Fig 1: Blower Motor Operation Malfunctioning Table

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

DIAGNOSTIC PROCEDURE
Check if blower motor rotates properly at each fan speed. Conduct checks as per Fig 1.
1. 1 : GO TO 2.
2. 2, 3, 4 : GO TO 8.
3. 5 : GO TO 10.
CHECK POWER SUPPLY FOR BLOWER MOTOR
Disconnect blower motor harness connector.

Fig 2: Blower Motor Voltage Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 3: 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 fuses (No. 10 and No. 11) at fuse block (J/B).
  - Check blower relay [located in fuse block (J/B)]. Refer to "WIRING DIAGRAM -- POWER ".
CHECK CIRCUIT CONTINUITY FOR BLOWER MOTOR
Turn fan control switch to any position except OFF.

Fig 4: Blower Motor Continuity Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 5: Checking Circuit Continuity For Blower Motor
Courtesy of NISSAN MOTOR CO., U.S.A.

Continuity should exist.

OK or NG
1. OK: GO TO 4.
2. NG: GO TO 5.
CHECK BLOWER MOTOR
(Refer to Electrical Components Inspection).

( "BLOWER MOTOR ").

OK or NG
1. OK: INSPECTION END
2. NG: Replace blower motor.
CHECK BLOWER MOTOR CIRCUIT BETWEEN BLOWER MOTOR AND RESISTOR
Reconnect blower motor harness connector.

Fig 6: Blower Motor And Resistor Voltage Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 7: Checking Blower Motor Circuit Between Blower Motor And Resistor
Courtesy of NISSAN MOTOR CO., U.S.A.

YES or No
1. Yes: GO TO 7.
2. No: GO TO 6.
CHECK CIRCUIT CONTINUITY BETWEEN BLOWER MOTOR AND RESISTOR
Disconnect blower motor and resistor harness connectors.

Fig 8: Blower Motor And Resistor Continuity Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 9: Checking Circuit Continuity Between Blower Motor And Resistor
Courtesy of NISSAN MOTOR CO., U.S.A.

Continuity should exist.

If OK, check harness for short.

OK or NG
1. OK: INSPECTION END
2. NG: Repair harness or connector.
CHECK GROUND CIRCUIT FOR FAN SWITCH
- Disconnect fan switch harness connector.
- Check circuit continuity between fan switch harness terminal and body ground.
  
  Fig 10: Fan Switch Voltage Table
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 11: Checking Ground Circuit For Fan Switch
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 8.
2. NG: Repair harness or connector.
CHECK BLOWER MOTOR RESISTOR
Refer to "BLOWER MOTOR RESISTOR ".

OK or NG
1. OK: GO TO 9.
2. NG: Replace blower motor resistor.
CHECK RESISTOR HARNESS CONNECTOR
Reconnect resistor harness connector.

OK or NG
1. 1 : GO TO 12.
2. 2, 3, 4 : GO TO 10.
CHECK FAN SWITCH CIRCUIT
Do approx. 12 volts exist between each fan switch harness connector terminal and body ground?

Fig 12: Fan Switch Circuit Voltage Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 13: Checking Fan Switch Circuit
Courtesy of NISSAN MOTOR CO., U.S.A.

YES or No
1. Yes: GO TO 12.
2. No: GO TO 11.
CHECK CIRCUIT CONTINUITY BETWEEN FAN SWITCH HARNESS TERMINAL AND RESISTOR HARNESS TERMINAL

Fig 14: Fan Switch Harness Terminal And Resistor Harness Terminal Voltage Table
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 15: Checking Circuit Continuity Between Fan Switch Harness Terminal And Resistor Harness Terminal
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
1. OK: Check harness for short.
2. NG: Repair harness or connector.
CHECK FAN SWITCH
Refer to "FAN SWITCH ".

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