AIR CONDITIONING SYSTEM(for Manual Air Conditioning System) Blower Motor Circuit

DESCRIPTION

A0059DIE01

The blower with fan motor sub-assembly is operated by 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

A0052ITE12
*a from HTR Fuse
*b Blower with Fan Motor Sub-assembly
*c Air Conditioning Amplifier Assembly

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BATTERY AND BODY GROUND)

    A0058V7E01
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Blower with Fan Motor Sub-assembly)

    1. Disconnect the D29 motor connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D29-3 (+B) - Body ground Always 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D29-1 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - AIR CONDITIONING AMPLIFIER)

    A0052WNE01
    Text in Illustration
    *1

    Front view of wire harness connector

    (to Blower with Fan Motor Sub-assembly)
    *2

    Rear view of wire harness connector

    (to Air Conditioning Amplifier Assembly)

    1. Disconnect the D101 amplifier connector.

    2. Disconnect the D29 motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D101-23 (BLW) - D29-2 (SI) Always Below 1 Ω
      D101-23 (BLW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)

    A005342E01
    Text in Illustration
    *1

    Rear view of wire harness connector

    (to Air Conditioning Amplifier Assembly)

    1. Disconnect the D101 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D101-14 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLW SIGNAL)


    1. A0055PAE01
      Text in Illustration
      *1

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected Click here.

    2. Using an oscilloscope, check the waveform.

      Measurement Condition
      Item Content
      Terminal No. (Symbol) D101-23 (BLW) - D101-14 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Ignition switch ON

      Blower switch LO
      OK
      Waveform is as shown in the illustration.

      Tech Tips

      Waveform varies with the blower level.


    OK

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here