Air Conditioning System Blower Motor Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
PERFORM ACTIVE TEST BY INTELLIGENT TESTER
INSPECT FUSE
CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND)
CHECK WIRE HARNESS (BLOWER MOTOR - BATTERY)
CHECK BLOWER MOTOR
CHECK WIRE HARNESS (A/C AMPLIFIER - BODY GROUND)
CHECK AIR CONDITIONING AMPLIFIER
AIR CONDITIONING SYSTEM - Blower Motor Circuit |
DESCRIPTION
The blower motor is operated by signals from the A/C amplifier. Blower motor speed signals are transmitted by changes in the duty ratio.Duty Ratio:The duty ratio is the ratio of the blower motor ON time (A) to the total of the blower motor ON and OFF time (A + B).The blower motor controller controls the blower motor speed.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and push the intelligent tester main switch on.
Select the item below in the Active Test and then check that the relay operates.
A/C amplifier:Item
| Test Details / Display
(Range)
| Diagnostic Note
|
Blower Motor
(Blower Motor)
| Blower motor /
Min.: Level 0, Max.: Level 31
| -
|
Result:OK
| A
|
NG (blower motor does not operate)
| B
|
NG (blower motor operates but does not change speed)
| C
|
| A |
|
|
|
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
Remove the HEATER fuse and ALT fuse from the engine room No. 1 junction block.
Measure the resistance of the fuses.
- Standard resistance:
Tester Item
| Condition
| Specified Condition
|
HEATER fuse
| Always
| Below 1 Ω
|
ALT fuse
| Always
| Below 1 Ω
|
| 3.CHECK WIRE HARNESS (BLOWER MOTOR - BODY GROUND) |
Disconnect the A50 or k1 blower motor connector.
Measure the resistance of the wire harness side connector.
- Standard resistance:
Tester Item
| Condition
| Specified Condition
|
A50-1 (GND) *1 - Body ground
| Always
| Below 1 Ω
|
k1-1 (GND) *2 - Body ground
| Always
| Below 1 Ω
|
- HINT:
- *1: 3GR-FE, 3GR-FSE
- *2: 3UZ-FE
| | REPAIR OR REPLACE HARNESS AND CONNECTOR |
|
|
| 4.CHECK WIRE HARNESS (BLOWER MOTOR - BATTERY) |
Disconnect the A50 or k1 blower motor connector.
Measure the voltage of the wire harness side connector.
- Standard voltage:
Tester Item
| Condition
| Specified Condition
|
A50-3 (+B) *1 - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
k1-3 (+B) *2 - Body ground
| Engine switch on (IG)
| 10 to 14 V
|
- HINT:
- *1: 3GR-FE, 3GR-FSE
- *2: 3UZ-FE
| | REPAIR OR REPLACE HARNESS AND CONNECTOR |
|
|
Disconnect the A/C amplifier connector.
Connect the blower motor connector.
Measure the voltage of the connector.
- Standard voltage:
Tester Item
| Condition
| Specified Condition
|
2 (SI) - Body ground
| Engine switch on (IG)
| 4.5 to 5.5 V
|
| 6.CHECK WIRE HARNESS (A/C AMPLIFIER - BODY GROUND) |
Disconnect the L52 A/C amplifier connector.
Measure the voltage of the wire harness side connector.
- Standard voltage:
Tester Item
| Condition
| Specified Condition
|
L52-11 (BLW) - Body ground
| Engine switch on (IG)
| 4.5 to 5.5 V
|
| | REPAIR OR REPLACE HARNESS AND CONNECTOR |
|
|
| 7.CHECK AIR CONDITIONING AMPLIFIER |
Remove the A/C amplifier with its connectors still connected.
Turn the engine switch on (IG).
Turn the blower switch ON (Lo).
Measure the waveform between terminal L52-11 (BLW) of the A/C amplifier and body ground.
- OK:
- Waveform is as shown in the illustration.
- HINT:
- Waveform varies with the blower level.
Item
| Contents
|
Tool setting
| 2 V / DIV., 500 μs / DIV.
|
Vehicle condition
| Engine switch on (IG)
Blower switch ON (Lo)
|
| | REPLACE AIR CONDITIONING AMPLIFIER |
|
|
