Compressor Control System

COMPRESSOR CONTROL SYSTEM

Air Conditioning System Wiring Schematic:

1) When the A/C switch and fan switch are turned ON, the A/C relay activates. The compressor is turned on, and then the main and sub fans also operate. Blower relay operates to direct the air flowrate determined by FAN switch position.

2) The thermo amplifier activates to stop the main and sub fans, and disengage compressor clutch.

3) When the "High-Low" pressure switch operates, it disengages the compressor clutch, and the main and sub fans are stopped.



COMPRESSOR CLUTCH "ON" DELAY SYSTEM




- When air conditioning system relay operates, a signal is entered into engine control module. Engine control module then judges engine operation and activates A/C relay. Maximum clutch "ON" delay occurs 0.8 seconds after A/C relay activates.


THERMO CONTROL AMPLIFIER




- The thermo control amplifier disconnects the magnet clutch circuit to prevent the evaporator from becoming frosted when the temperature of the evaporator discharge air drops close to 3°C (37°F). As the evaporator is cooled, the thermistor (located on the evaporator fin) interrupts the "base" current of the amplifier. This in turn deenergizes the A/C relay coil, which in turn disconnects the magnet clutch circuit.



ACCELERATION CUT SYSTEM




- The A/C relay turns the A/C system on or off. The on-off operation of the switch is transmitted to the ECU.

- The A/C relay breaks the current flow to the compressor, through the use of an output signal from the ECU, for a certain period of time when a "full-throttle" signal (emitted from the throttle sensor) enters the ECU while the compressor is operating. This prevents the degradation of acceleration performance and stabilizes. A/C relay located in the main fuse box.


I.S.C.







- The I.S.C. increases engine idle speed when the compressor is turned ON.

- The Engine Control module activates the idle speed control solenoid valve in advance to control the amount of by-pass air flowing through the throttle body in relation to the signal emitted from the A/C switch, so that the proper idle speed specified for each engine load is achieved.