Blower Motor Circuit

HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Manual Air Conditioning System): Blower Motor Circuit
- Blower Motor Circuit

DESCRIPTION

The blower with fan motor sub-assembly operates according to signals from the air conditioning amplifier assembly. The blower with fan motor sub-assembly speed signals are transmitted by changes in the duty ratio.

Duty Ratio:

The duty ratio is the ratio of the blower with fan motor sub-assembly on time (T1) to the total of the blower with fan motor sub-assembly on and off time (T2).

The air conditioning amplifier assembly controls the blower with fan motor sub-assembly speed.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (BLOWER WITH FAN MOTOR)

(a) Select the Active Test, use the Techstream to generate a control command, and then check that the blower with fan motor sub-assembly operates Air Conditioning System (for Manual Air Conditioning System).

Air Conditioner

OK:

Blower with fan motor sub-assembly operates and blower motor speed changes.

NG -- CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - BATTERY AND BODY GROUND)

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Air Conditioning System (for Manual Air Conditioning System)

2. CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - BATTERY AND BODY GROUND)

(a) Disconnect the F43 motor connector.

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

Standard Voltage:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BLOWER WITH FAN MOTOR AND BODY GROUND)

(a) Disconnect the F42 amplifier connector.

(b) Disconnect the F43 motor connector.

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

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLW SIGNAL)

(a) Remove the air conditioning amplifier assembly with its connectors still connected Removal.

(b) Using an oscilloscope, check the waveform.

Measurement Condition

OK:

Waveform is as shown in the illustration.

Text in Illustration

HINT
Waveform varies with the blower level.

NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal
OK -- Continue to next step.

5. REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY

(a) Replace the blower with fan motor sub-assembly with a new or normally functioning one Removal.

(b) Operate the blower with fan motor sub-assembly to check that it functions properly.

OK:

Blower with fan motor sub-assembly operates normally.

NG -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

OK -- END (BLOWER WITH FAN MOTOR SUB-ASSEMBLY IS FAULTY)