Diagnosis Procedure

1. Turn ignition switch OFF.
2. Check 15A fuses [Nos. 17 and 27, located in fuse block (J/B)].
   NOTE: Refer to the appropriate Wiring Diagram [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.

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

   +		-		Voltage (Approx.)
   Blower motor
   Connector	Terminal
   M31	4	Ground		Battery voltage

Is the inspection result normal?

YES

GO TO 3 .

NO

GO TO 6 .

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

   Blower motor		-		Continuity
   Connector	Terminal
   M31	1	Ground		Yes

Is the inspection result normal?

YES

GO TO 4 .

NO

Repair harness or connector.

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

   Blower motor		A/C auto amp.		Continuity
   Connector	Terminal	Connector	Terminal
   M31	3	M37	18	Yes

Is the inspection result normal?

YES

GO TO 5 .

NO

Repair the harness or connector.

1. Reconnect 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 blower motor harness connector and ground using an oscilloscope.
   NOTE: Calculate drive signal duty ratio as shown in the figure.

   T2 = Approx. 1.6 ms

   Courtesy of NISSAN NORTH AMERICA, INC.

   Blower motor		Condition	Duty ratio (Approx.)
   Connector	Terminal	Fan speed (manual) VENT mode
   M31	3	1st	25 %
   		2nd	33 %
   		3rd	41 %
   		4th	51 %
   		5th	61 %
   		6th	69 %
   		7th	81 %

Is the inspection result normal?

YES

Replace blower motor. Refer to Removal and Installation .

NO

Replace A/C auto amp. Refer to Removal and Installation .

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

   Fuse block (J/B)		-	Continuity
   Connector	Terminal
   M4	13R	Ground	Yes

Is the inspection result normal?

YES

GO TO 7 .

NO

Repair harness or connector.

Check front blower motor relay. Refer to Component Inspection (Front Blower Motor Relay) .

Is the inspection result normal?

YES

Repair harness or connector between blower motor and fuse block (J/B).

NO

Replace front blower motor relay.