Diagnosis Procedure

BLOWER MOTOR


Description


COMPONENT DESCRIPTION

Brush-less Motor





The blower motor utilizes a brush-less motor with a rotating magnet.
Quietness is improved over previous motors where the brush was the point of contact and the coil rotated.




BLOWER MOTOR


Diagnosis Procedure

1.CHECK POWER SUPPLY FOR THE BLOWER MOTOR
1. Turn ignition switch OFF.
2. Disconnect the blower motor connector.
3. Turn ignition switch ON.
4. Check voltage between the blower motor harness connector and ground.





Is the inspection result normal?
YES - GO TO 2.
NO - GO TO 5.
2.CHECK THE BLOWER MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between the blower motor harness connector and ground.





Is the inspection result normal?
YES - GO TO 3.
NO - Repair harness or connector.
3.CHECK CIRCUIT CONTINUITY BETWEEN THE BLOWER MOTOR AND UNIFIED METER AND A/C AMP.
1. Disconnect unified meter and A/C amp. connector.
2. Check continuity between the blower motor harness connector and unified meter and A/C amp. harness connector.





3. Check continuity between the blower motor harness connector and ground.





Is the inspection result normal?
YES - GO TO 4.
NO - Repair harness or connector.
4.CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL
1. Reconnect the blower motor connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Set MODE switch to VENT position.
4. Change fan speed from Lo to Hi, and check duty ratios between the blower motor harness connector and ground by using an oscilloscope.

NOTE:
Calculate the drive signal duty ratio as shown in the figure.





T2 = 1.6 ms






Is the inspection result normal?
YES - Replace the blower motor after confirming the fan air flow does not change.
NO - Replace unified meter and A/C amp.
5.CHECK POWER VOLTAGE OF BLOWER RELAY
1. Turn ignition switch OFF.
2. Remove blower relay. Diagrams.
3. Turn ignition switch ON.
4. Check the voltage between blower relay fuse block terminals and ground. Description and Operation for relay terminal assignment.





Is the inspection result normal?
YES - GO TO 6.
NO - Check ignition power supply circuit. Ignition Power Supply.
6.CHECK BLOWER RELAY
1. Turn ignition switch OFF.
2. Install blower relay. Diagrams.
3. Check operation sound of the blower relay after switching ignition switch ON.
Is the inspection result normal?
YES - GO TO 7.
NO - Replace blower relay.
7.CHECK FUSE
Check fuse 15A [Nos 21 and 22, located in the fuse block (J/B). Diagrams.
Is the inspection result normal?
YES - Repair harness or connector.
NO - Be sure to eliminate cause of malfunction before installing new fuse.