See Figure 1
The air conditioning system used on Ford Mustang vehicles is the fixed orifice tube-cycling clutch type. The system components consist of the compressor, magnetic clutch, condenser, evaporator, suction accumulator/drier and the necessary connecting refrigerant lines. The fixed orifice tube assembly is the restriction between the high and low pressure liquid refrigerant and meters the flow of liquid refrigerant into the evaporator core. Evaporator temperature is controlled by sensing the pressure within the evaporator with the clutch cycling pressure switch. The pressure switch controls compressor operation as necessary to maintain the evaporator pressure within specified limits.