Heating and Air Conditioning: Description and Operation

GENERAL INFORMATION
The heater system uses a two-way-flow full-air-mix system that features high performance and low operating noise. It includes an independent face air blowing function and a cool air bypass function.

The A/C system is basically the same as the conventional system, but a new refrigerant system has been adopted as a response to restrictions on the use of chlorofluorocarbons.


OPERATION

Condenser fan and radiator fan control
For the operation of each fan, refer to Troubleshooting.

Compressor control
When operating the air conditioning switch
The air thermo sensor, which senses the temperature of the air flowing out of the evaporator, deactivates the compressor at -2 °C (28 °F) or below.

Here, the engine coolant temperature sensor senses the temperature of engine coolant, and turns off the compressor at 115 °C (239 °F) or higher temperatures.

A/C Compressor Relay ON Conditions:

The dual pressure switch turns OFF when the refrigerant pressure becomes excessively high or low, thus protecting the compressor circuit. (See Table.)

When these two sensors are all activated, the dual pressure switch is ON, and the ignition switch, blower switch, and air conditioning switch are ON, the A/C compressor relay is energized.

When operating the air outlet changeover control knob
When the air outlet changeover control knob is moved to DEF or DEF/FOOT position, the micro switch, which is connected in series to the air conditioning switch, is turned on. The other compressor control than the above is the same as that when operating the air conditioning switch.