Front Blower Motor

FRONT BLOWER MOTOR

Diagnosis Procedure

Regarding Wiring Diagram information, refer to "Wiring Diagram" [1][2]Electrical Diagrams.

1. CHECK FUSE

1.Turn ignition switch OFF.
2.Check 15A fuses [Nos. 17 and 27, located in fuse block (J/B)].
NOTE:
Refer to "Terminal Arrangement" Fuse Block - Junction Box (J/B).
Is the inspection result normal?
YES- GO TO 2.
NO- Replace the blown fuse after repairing the affected circuit.

2. CHECK FRONT BLOWER MOTOR POWER SUPPLY

1.Disconnect front blower motor connector.
2.Turn ignition switch ON.
3.Check voltage between front blower motor harness connector and ground.





Is the inspection result normal?
YES- GO TO 3.
NO- GO TO 6.

3. CHECK FRONT BLOWER MOTOR GROUND CIRCUIT

1.Turn ignition switch OFF.
2.Check continuity between front blower motor harness connector and ground.





Is the inspection result normal?
YES- GO TO 4.
NO- Repair harness or connector.

4. CHECK FRONT BLOWER MOTOR CONTROL SIGNAL CIRCUIT

1.Disconnect A/C auto amp. connector.
2.Check continuity between front blower motor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES- GO TO 5.
NO- Repair the harness or connector.

5. CHECK FRONT BLOWER MOTOR CONTROL SIGNAL

Revision: March 20122013 Infiniti JX
1.Reconnect front blower motor connector and A/C auto amp. connector.
2.Turn ignition switch ON.
3.Operate MODE switch to set air outlet to VENT.
4.Change fan speed from Lo to Hi, and check duty ratios between front blower motor harness connector and ground by using an oscilloscope.
NOTE:
Calculate drive signal duty ratio as shown in the figure.





T2 = Approx. 1.6 ms





Is the inspection result normal?
YES- Replace front blower motor. Refer to "FRONT BLOWER MOTOR : Removal and Installation" Front Blower Motor.
NO- Replace A/C auto amp. Refer to "Removal and Installation" Removal and Installation.

6. CHECK FRONT BLOWER MOTOR RELAY GROUND CIRCUIT

1.Turn ignition switch OFF.
2.Check continuity between fuse block (J/B) harness connector and ground.





Is the inspection result normal?
YES- GO TO 7.
NO- Repair harness or connector.

7. CHECK FRONT BLOWER RELAY

Check front blower motor relay. Refer to "Component Inspection (Front Blower Motor Relay)" .
Is the inspection result normal?
YES- Repair harness or connector between front blower motor and fuse block (J/B).
NO- Replace front blower relay.


Component Inspection (Front Blower Motor)


1. CHECK FRONT BLOWER MOTOR

1.Connect battery voltage to terminal 1 of front blower motor.
2.Connect ground to terminal 2 of front blower motor.
Does the front blower fan operate?
YES- Intermittent incident. Refer to "Intermittent Incident" Intermittent Incident.
NO- Replace front blower motor. Refer to "FRONT BLOWER MOTOR : Removal and Installation" Front Blower Motor.


Component Inspection (Front Blower Motor Relay)


1. CHECK BLOWER RELAY

Revision: March 20122013 Infiniti JX
1.Turn ignition switch OFF.
2.Remove front blower motor relay.





3.Check continuity between front blower motor relay terminals 3
and 5 when voltage is supplied between terminals 1 and 2.





Is the inspection result normal?
YES- Inspection End.
NO- Replace front blower motor relay.
Revision: March 20122013 Infiniti JX