NOTE: Proper Air Conditioning (A/C) system diagnosis on a vehicle's compressor is dependent on correct refrigerant system charge and tested in ambient temperatures above 21.1°C (70°F).
Variable displacement compressors have a swash plate that rotates to reciprocate pistons, which compresses refrigerant. Variable displacement compressors change the swash plate angle to change the refrigerant displacement. The externally controlled variable displacement compressor changes the swash plate angle in accordance with an electrical signal from the PCM. Externally controlled variable displacement compressor manages displacement by controlling refrigerant differential pressure before and after a throttle at the discharge side; achieving precise cooling capability control in accordance with cabin environment and driving conditions.
The PCM sends a PWM signal to the solenoid in the compressor to control the compressor displacement based upon the:
Evaporator temperature Ambient air temperature Engine RPM Vehicle speed A/C high side pressure Intake air temperature
Fixed Displacement A/C Compressor (3.7L, 5.0L and 5.2L)
NOTE: Proper Air Conditioning (A/C) system diagnosis on a vehicle's compressor is dependent on correct refrigerant system charge and tested in ambient temperatures above 21.1°C (70°F).
The fixed displacement compressor has:
a non-serviceable shaft seal. a serviceable pressure relief valve installed in the rear of the compressor to protect the refrigerant system against excessively high refrigerant pressures. a serviceable A/C clutch and field coil. Uses Motorcraft® PAG Refrigerant Compressor Oil YN-12-D. This oil contains special additives required for the A/C compressor. The oil may have some slightly dark-colored streaks while maintaining normal oil viscosity. This is normal for this A/C compressor because of break-in wear that can discolor the oil.
Fixed displacement A/C compressors are always at 100% displacement. The pistons are placed around an angled plate (swash plate) and are pushed back and forth as the plate rotates. Cooling performance is controlled by switching the compressor clutch on or off depending upon the evaporator temperature.
Condenser
The A/C condenser is an aluminum fin-and-tube design heat exchanger. It cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat, and condenses gas to liquid refrigerant as it is cooled. The receiver drier is mounted on the left side of the condenser.
Receiver Drier
The receiver drier stores high-pressure liquid. The desiccant bag mounted inside the receiver drier removes any retained moisture from the refrigerant.
Thermostatic Expansion Valve (TXV)
The Thermostatic Expansion Valve (TXV) is located at the evaporator core inlet and outlet tubes at the center rear of the engine compartment. The TXV provides a restriction to the refrigerant flow and separates the
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.