Automatic Air Conditioning

BLOWER MOTOR

Diagnosis Procedure


1. CHECK FUSE

1.Turn ignition switch OFF.
2.Check following fuses.
-10A fuse [No. 15, located in fuse block (J/B)]
-15A fuses [Nos. 14 and 16, located in fuse block (J/B)]
NOTE:
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 if a fuse is blown.

2. CHECK BLOWER MOTOR POWER SUPPLY

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





Is the inspection result normal?
YES- GO TO 4.
NO- GO TO 3.

3. CHECK BLOWER RELAY

1.Turn ignition switch OFF.
2.Check blower relay. .
Is the inspection result normal?
YES- Repair harness or connector between blower motor and fuse.
NO- Replace blower relay.

4. CHECK BLOWER MOTOR CONTROL CIRCUIT

1.Turn ignition switch OFF.
2.Connect blower motor connector.
3.Disconnect power transistor connector.
4.Turn ignition switch ON.
5.Check voltage between power transistor harness connector and ground.





Is the inspection result normal?
YES- GO TO 6.
NO- GO TO 5.

5. CHECK BLOWER MOTOR CONTROL CIRCUIT FOR OPEN

1.Turn ignition switch OFF.
2.Disconnect blower motor connector.
3.Check continuity between power transistor harness connector and blower motor harness connector.





Is the inspection result normal?
YES- Replace blower motor. Removal And Installation.
NO- Repair harness or connector.

6. CHECK A/C AUTO AMP. IGNITION POWER SUPPLY

1.Turn ignition switch OFF.
2.Disconnect A/C auto amp.
3.Turn ignition switch ON.
4.Check voltage between A/C auto amp. harness connector and ground.





Is the inspection result normal?
YES- GO TO 7.
NO- Repair harness or connector between A/C auto amp. and fuse.

7. CHECK POWER TRANSISTOR IGNITION POWER SUPPLY

Check voltage between power transistor harness connector and ground.





Is the inspection result normal?
YES- GO TO 8.
NO- Repair harness or connector between power transistor and fuse.

8. CHECK POWER TRANSISTOR GROUND CIRCUIT FOR OPEN

1.Turn ignition switch OFF.
2.Check continuity between power transistor harness connector and ground.





Is the inspection result normal?
YES- GO TO 9.
NO- Repair harness or connector.

9. CHECK POWER TRANSISTOR CONTROL SIGNAL

1.Connect blower motor connector and A/C auto amp. connector.
2.Turn ignition switch ON.
3.Set air outlet to VENT.
4.Change fan speed from 1st - 7th, and check duty ratios between blower motor harness connector and ground by using an oscilloscope.
NOTE:
Calculate the drive signal duty ratio as shown in the figure.
T2 = Approx. 1.6 ms





Is the inspection result normal?
YES- Replace power transistor. Power Transistor.
NO- GO TO 10.

10. CHECK POWER TRANSISTOR CONTROL SIGNAL CIRCUIT FOR OPEN

1.Turn ignition switch OFF.
2.Disconnect power transistor connector and A/C auto amp. connector.
3.Check continuity between power transistor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES- GO TO 11.
NO- Repair harness or connector.

11. CHECK POWER TRANSISTOR CONTROL SIGNAL CIRCUIT FOR SHORT

Check continuity between power transistor harness connector and ground.





Is the inspection result normal?
YES- Replace A/C auto amp. Removal And Installation.
NO- Repair harness or connector.


Component Inspection (Blower Motor)


1. CHECK BLOWER MOTOR

1.Remove blower motor. Removal And Installation.
2.Check that there is not any mixing foreign object in the blower motor.
Is the inspection result normal?
YES- GO TO 2.
NO- Replace blower motor. Removal And Installation.

2. CHECK BLOWER MOTOR

Check that there is not breakage or damage in the blower motor.
Is the inspection result normal?
YES- GO TO 3.
NO- Replace blower motor. Removal And Installation.

3. CHECK BLOWER MOTOR

Check that blower motor turns smoothly.
Is the inspection result normal?
YES- INSPECTION END
NO- Replace blower motor. Removal And Installation.


Component Inspection (Blower Relay)


1. CHECK BLOWER RELAY

1.Remove blower relay. Fuse Block - Junction Box (J/B).





2.Check continuity between blower relay terminal 3 and 5 when the voltage is supplied between terminal 1 and 2.





Is the inspection result normal?
YES- INSPECTION END
NO- Replace blower relay.