Blower Motor Circuit

DESCRIPTION

1. The duty ratio is the ratio of the period of continuity in one cycle. For example, A is the period of continuity in one cycle, and B is the period of non-continuity.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

1. READ VALUE OF INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON and push the intelligent tester main switch on.

3. Select the item below in the DATA LIST, and read the display on the intelligent tester.

OK:

The display is as specified in the normal condition.

NG	Go to step 2

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2. PERFORM ACTIVE TEST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the ignition switch ON and push the intelligent tester main switch on.

3. Select the item below in the ACTIVE TEST and then check that the blower motor operates.

OK:

Blower motor operates and blower level changes.

NG	Go to step 3

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

3. PERFORM ACTUATOR CHECK

1. Set the actuator check mode (Click here).

2. Press the blower switch to set the step operation.

3. Check for air flow level by hand.

OK:

Blower level changes in accordance with each display code.

NG	Go to step 4

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

4. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - A/C AMPLIFIER ASSEMBLY)

1. Disconnect the connector from the A/C amplifier assembly and the blower motor controller.

2. Measure the resistance according to the value(s) in the table below.

   Resistance:

   Tester connection (Symbols)	Condition	Specified condition
   A11-9 (BLW) - B3-2	Always	Below 1 Ω
   A11-9 (BLW) - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

5. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BODY GROUND)

1. Measure the resistance according to the value(s) in the table below.

   Resistance:

   Tester connection	Condition	Specified condition
   B3-1 - Body ground	Always	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BLOWER MOTOR)

1. Disconnect the connector from the blower motor.

2. Measure the voltage according to the value(s) in the table below.

   Voltage:

   Tester connection	Condition	Specified condition
   B2-2 - Body ground	Ignition switch ON Blower switch: ON	10 to 14 V
   B3-3 - Body ground	Ignition switch ON Blower switch: ON	10 to 14 V
   B2-2 - Body ground	Ignition switch ON Blower switch: OFF	Below 1 V
   B3-3 - Body ground	Ignition switch ON Blower switch: OFF	Below 1 V

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BLOWER MOTOR)

1. Measure the resistance according to the value(s) in the table below.

   Resistance:

   Tester connection	Condition	Specified condition
   B2-1 - B3-4	Always	Below 1 Ω
   B2-1 - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

8. INSPECT COOLING UNIT MOTOR SUB-ASSEMBLY W/FAN

1. Remove the cooling unit motor sub-assembly w/ fan.

2. Connect the negative (-) lead connected to terminal 1 of the blower motor connector, the positive (+) lead to terminal 2.

OK:

Blower motor operates smoothly.

NG	REPLACE COOLING UNIT MOTOR SUB-ASSEMBLY W/FAN

OK

9. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

1. Reconnect the connector to the A/C amplifier assembly.

2. Remove the A/C amplifier assembly with the connectors still connected.

3. Turn the ignition switch to the ON position.

4. Blower speed switch is at "LO".

5. Measure the waveform between terminal BLW (A11-9) of the A/C amplifier assembly and body ground.

   OK:

   Waveform operate as shown in the illustration.
   

   HINT:

   Waveform cycle varies with the blower level.

NG	REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

OK
REPLACE BLOWER MOTOR CONTROLLER