AIR CONDITIONING SYSTEM Air Conditioning Compressor Magnetic Clutch Circuit

DESCRIPTION

When the air conditioning amplifier assembly is turned on, a magnetic clutch on signal is sent from the MGC terminal of the air conditioning amplifier assembly. Then, the engine room junction block assembly turns on to operate the magnetic clutch assembly.

WIRING DIAGRAM

B000JBKE07

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. Using a voltmeter, check the signal reading of the engine room junction block assembly Click here.

      OK
      A normal signal reading is output.

    NG

    INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULT OF SIGNAL READING CHECK) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND)


    1. Remove the engine room junction block assembly from the engine room relay block and junction block assembly Click here.

      B000HX2E05

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A-1 (BATT) - Body ground Always 11 to 14 V
      B-1 (ALT) - 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
      1F-3 (GND1) - Body ground Always Below 1 Ω
      1G-4 (GND2) - Body ground Always Below 1 Ω
      Text in Illustration
      *a

      Component without engine room junction block assembly

      (Engine Room Junction Block Assembly)

      		 - -

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - MAGNETIC CLUTCH ASSEMBLY)


    1. Disconnect the E73 compressor and magnet clutch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1M-1 (MGCT) - E73-3 (MG+) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT COMPRESSOR AND MAGNET CLUTCH


    1. Disconnect the a2 magnetic clutch assembly connector.

    2. B000LXIE01
      Text in Illustration
      *a

      Component without harness connected

      (Compressor and Magnet Clutch)
      *b

      Component without harness connected

      (Magnetic Clutch Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E73-3 (MG+) - a2-1 Always Below 1 Ω

    NG

    REPLACE COMPRESSOR AND MAGNET CLUTCH Click here

    OK

  5. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY


    1. Disconnect the I77 air conditioning amplifier assembly connector.

    2. Reconnect the engine room junction block assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I77-20 (MGC) - Body ground Ignition switch off Below 1 V
      I77-20 (MGC) - Body ground Ignition switch ON 11 to 14 V

    NG

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY) Click here

    OK

  6. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Reconnect the I77 air conditioning amplifier assembly connector.

    2. B000JQME11
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I77-20 (MGC) - Body ground

      Ignition switch ON

      A/C switch: off

      		 11 to 14 V
      I77-20 (MGC) - Body ground

      Ignition switch off

      A/C switch: on

      		 Below 1 V

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I77-20 (MGC) - 1F-9 (MCLS) Always Below 1 Ω
      I77-20 (MGC) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here