Diagnostic Procedure For Blower Motor

WARNING: This page is about a different car, the 2007 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: Blower motor operation is malfunctioning under starting blower speed control.

Fig 1: Identifying Blower Motor Circuit Diagram

CHECK FUSES
Check 15A fuses [No. 24 and 27, (located in the fuse and fusible link box)]. For fuse layout, refer to "FUSE AND FUSIBLE LINK BOX ".

Fuses are good.

OK or NG

OK: GO TO 2.

NG: GO TO 10.
CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector.
3. Turn ignition switch ON.
4. Turn the front blower control dial to select any mode except off.
5. Check voltage between front blower motor harness connector M62 terminal 1 and ground.
  1 - Ground : Battery voltage
OK or NG

OK: GO TO 12.

NG: GO TO 3.

Fig 2: Checking Voltage Between Front Blower Motor Harness Connector M62 Terminal 1 And Ground

CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT

Turn ignition switch OFF.
Disconnect front blower motor relay.

Check voltage between front blower motor relay harness connector E22 terminals 5 and 7 and ground.

VOLTAGE CONDITION CHART

A
Connector	(+)	(-)	Condition	Voltage (Approx.)
Front blower motor relay: E22	5	Ground	Front blower motor relay power supply	Battery voltage
Front blower motor relay: E22	7	Ground	Front blower motor relay power supply	Battery Voltage

Fig 3: Checking Voltage Between Front Blower Motor Relay Harness Connector E22 Terminals 5 And 7 And Ground

OK or NG

OK: GO TO 4.

NG: Repair harness or connector.

CHECK FRONT BLOWER MOTOR RELAY
Refer to "FRONT BLOWER MOTOR RELAY ".

OK or NG

OK: GO TO 5.

NG: Replace front blower motor relay.

CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN

Turn ignition switch OFF.
Disconnect blower motor relay connector and front blower motor connector.

Check continuity between front blower motor relay harness connector E22 (A) terminals 3 and 6 and front blower motor harness connector M62 (B) terminal 1.

CONTINUITY REFERENCE CHART

A		B
Connector	Terminal	Connector	Terminal	Continuity
Front blower motor relay: E22	3	Front blower motor: M62	1	Yes
Front blower motor relay: E22	6	Front blower motor: M62	1	Yes

Fig 4: Checking Continuity Between Harness Connector E22 (A) Terminals 3 ,6 And Harness Connector M62 (B) Terminal 1

OK or NG

OK: GO TO 6.

NG: Repair harness or connector.

CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN

Disconnect variable blower control harness connector.

Check continuity between front blower motor relay harness connector E22 (A) terminals 3 and 6 and variable blower control harness connector M122 (B) terminal 1.

CONTINUITY REFERENCE CHART

A		B
Connector	Terminal	Connector	Terminal	Continuity
Front blower motor relay: E22	3	Variable blower control: M122	1	Yes
Front blower motor relay: E22	6	Front blower motor: M122	1	Yes

Fig 5: Checking Continuity Between Connector E22 (A) Terminals 3 And 6 And Harness Connector M122 (B) Terminal 1

OK or NG

OK: GO TO 7.

NG: Repair harness or connector.

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector.
2. Check continuity between front air control harness connector M50 terminal 32 and variable blower control harness connector M122 terminal 2.
  32 - 2 : Continuity should exist.
OK or NG

OK: GO TO 8.

NG: Repair harness or connector.

Fig 6: Checking Continuity Between Front Air Control Harness Connector M50 Terminal 32 And Connector M122 Terminal 2
CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between front blower motor relay connector E22 terminal 1 and ground.
  1 - Ground : Battery voltage
OK or NG

OK: GO TO 9.

NG: Repair harness or connector.

Fig 7: Checking Voltage Between Front Blower Motor Relay Connector E22 Terminal 1 And Ground
CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between front blower motor relay connector E22 terminal 2 and front air control harness connector M50 terminal 38.
  2 - 38 : Continuity should exist.
OK or NG

OK: Replace front air control. Refer to "FRONT AIR CONTROL ".

NG: Repair harness or connector.

Fig 8: Checking Continuity Between Front Blower Motor Relay Connector E22 Terminal 2 And Connector M50 Terminal 38
REPLACE FUSES
1. Replace fuses.
2. Activate the front blower motor.
3. Do fuses blow?
Yes or No

YES: GO TO 11.

NO: Inspection End.
CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector and variable blower control connector.
3. Check continuity between variable blower control harness connector M122 terminal 1 and ground.
  1 - Ground : Continuity should not exist.
OK or NG

OK: GO TO 12.

NG: Repair harness or connector.

Fig 9: Checking Continuity Between Variable Blower Control Harness Connector M122 Terminal 1 And Ground
CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector.
2. Check continuity between front air control harness connector M50 terminal 32 and variable blower control harness connector M122 terminal 2.
  32 - 2 : Continuity should exist.
OK or NG

OK: Check blower motor. If OK, replace variable blower control. Refer to "FRONT BLOWER MOTOR ".

NG: Repair harness or connector.

Fig 10: Checking Continuity Between Front Air Control Harness Connector M50 Terminal 32 And Connector M122 Terminal 2