Refrigerant System

REFRIGERANT SYSTEM
The A/C refrigerant system is a clutch cycling orifice tube type. The system components are:
- A/C compressor
- A/C clutch
- A/C condenser core
- A/C evaporator core
- suction accumulator/drier
- the necessary connecting refrigerant lines

System operation is controlled by the following:
- A/C-heater function selector switch
- A/C evaporator core orifice
- A/C cycling switch
- A/C compressor pressure relief valve
- A/C pressure cut-off switch

The refrigerant system incorporates an A/C compressor controlled by an A/C cycling switch.

The A/C cycling switch:
- senses pressure in the A/C evaporator core to control operation of the A/C compressor.
- uses this method of control to stop operation of the A/C compressor during ambient temperatures below approximately 10°C (50°F) and to prevent icing of the A/C evaporator core during normal system operation.

An A/C compressor relief valve is installed in the A/C manifold and tube to protect the refrigerant system against excessively high refrigerant pressures.

Operation of the A/C clutch is dependent on signals from the Powertrain Control Module (PCM). The system is programmed to interrupt A/C compressor operation when certain conditions exist. The A/C clutch can be shut off (or kept off) for several seconds:
- at engine start up.
- at high engine speeds.
- during acceleration.
- when the engine coolant temperature exceeds a predetermined temperature during low engine idle conditions (approximately 200 rpm below low idle specifications).

An A/C evaporator core orifice is used to meter the liquid refrigerant into the A/C evaporator core for A/C evaporator core cooling.