Diagnosis Procedure

BLOWER MOTOR


Description


BLOWER MOTOR





- The blower motor is installed in the RH side of A/C unit assembly.
- The blower motor adopts the forcible air cooling system and one-touch installation system without any screws.

POWER TRANSISTOR





- The power transistor attached to A/C unit assembly.





- The power transistor controls the transmitting voltage to blower motor base on the gate voltage from A/C auto amp.
- The power transistor is set for low voltage drop, therefore it does not require high relay while transmitting max voltage to blower motor.





BLOWER MOTOR


Diagnosis Procedure

1.CHECK FUSE
Check 15A fuses [Nos. 15 and 17, located in the fuse block (J/B)].

NOTE:
Diagrams.
Is inspection result normal?
YES - GO TO 2.
NO - Replace the corresponding fuse.
2.CHECK POWER SUPPLY OF BLOWER MOTOR
1. Turn the ignition switch OFF.
2. Disconnect the blower motor connector.
3. Turn the ignition switch ON.
4. Check voltage between blower motor harness connector and the ground.





Is the inspection result normal?
YES - GO TO 4.
NO - GO TO 3.
3.CHECK BLOWER MOTOR RELAY
1. Turn the ignition switch OFF.
2. Check the blower motor relay. Component Inspection.
Is inspection result normal?
YES - Repair the harness or connector between blower motor and fuse.
NO - Replace the blower motor relay.
4.CHECK VOLTAGE BETWEEN POWER TRANSISTOR AND GROUND
1. Connect the blower motor connector.
2. Disconnect the power transistor connector.
3. Turn the ignition switch ON.
4. Check voltage between power transistor harness connector and the ground.





Is inspection result normal?
YES - GO TO 6.
NO - GO TO 5.
5.CHECK CONTINUITY BETWEEN BLOWER MOTOR AND POWER TRANSISTOR
1. Turn the ignition switch OFF.
2. Disconnect the blower motor connector.
3. Check continuity between blower motor harness connector and power transistor harness connector.





Is the inspection result normal?
YES - Replace the blower motor.
NO - Repair the harnesses or connectors.
6.CHECK VOLTAGE BETWEEN POWER TRANSISTOR AND GROUND
Check voltage between power transistor harness connector and the ground.





Is inspection result normal?
YES - GO TO 7.
NO - Replace the harness or connector between power transistor and fuse.
7.CHECK CONTINUITY BETWEEN POWER TRANSISTOR AND GROUND
Check continuity between power transistor harness connector and the ground.





Is inspection result normal?
YES - GO TO 8.
NO - Repair the harnesses or connectors.
8.CHECK A/C AUTO AMP. OUTPUT SIGNAL
1. Connect the blower motor connector and the A/C auto amp. connector.
2. Turn the ignition switch ON.
3. Set the mode position to VENT.
4. Change fan speed from Lo to Hi, and check duty ratios between blower motor harness connector and the 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 - GO TO 10.
NO - GO TO 9.
9.CHECK CONTINUITY BETWEEN POWER TRANSISTOR AND A/C AUTO AMP.
1. Turn the ignition switch OFF.
2. Disconnect the power transistor connector.
3. Disconnect the A/C auto amp. connector.
4. Check continuity between power transistor harness connector and A/C auto amp. harness connector.





Is the inspection result normal?
YES - Replace the A/C auto amp.
NO - Repair the harnesses or connectors.
10.CHECK CONTINUITY POWER TRANSISTOR SUB HARNESS





Check the sub harness continuity with the following figure.
Is the inspection result normal?
YES - Replace the power transistor.
NO - Repair the harnesses or connectors.