Air Conditioning

A/C Component Locations, Part 1:

A/C Component Locations, Part 2:

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

The refrigeration system operation is controlled by the:
^ 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 A/C evaporator core pressure to control A/C compressor operation.

The A/C pressure cut-off switch measures the A/C refrigerant pressure.

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

An A/C evaporator core orifice is installed in the condenser to evaporator tube to meter the liquid refrigerant into the A/C evaporator core.

A/C Compressor And Clutch Assembly - Clutch Components:

A/C Compressor and Clutch Assembly

NOTE:
^ Internal A/C compressor components are not repairable separately. The FS-10 A/C compressor is not repairable at the dealership level. The A/C clutch, A/C clutch pulley and shaft seal are repairable at the dealership level.
^ Replacement of the suction accumulator is not required when repairing the air conditioning system, except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The FS-10 is a swash plate design, 10-cylinder aluminum compressor. The A/C compressor main shaft is driven by an accessory drive belt from the engine crankshaft pulley.

An A/C clutch drives the A/C compressor shaft. When voltage is applied to the A/C clutch, the clutch plate and hub assembly (which is connected to the A/C compressor shaft) is drawn rearward by magnetic force toward the A/C clutch pulley. The magnetic force locks the clutch plate and hub assembly together as one unit.

When voltage is removed from the A/C clutch field coil, springs in the A/C clutch move the clutch plate away from the A/C clutch pulley and the A/C compressor shaft stops rotating.

A/C Compressor Pressure Relief Valve
The A/C compressor relief valve:
^ is incorporated in the compressor A/C manifold and tube.
^ relieves unusually high refrigerant system discharge pressure build-ups (3103 kPa and above).
^ prevents damage to the A/C compressor and other system components.
^ avoids total refrigerant loss by closing after the excessive pressure has been relieved.

A/C Condenser Core
The A/C condenser core:
^ is an aluminum fin and tube design heat exchanger located in front of the vehicle radiator.
^ cools compressed refrigerant gas by allowing air to pass over fins and tubes to extract heat and by condensing gas to liquid refrigerant as it is cooled.

Refrigerant Lines
The condenser to evaporator tube contains high pressure liquid refrigerant upstream of the A/C evaporator core orifice. The A/C manifold and tube is attached to the A/C compressor with O-ring seals.

A/C Evaporator Core

NOTE:
^ The evaporator core is not separately repairable, it is repaired only with the evaporator core housing assembly.
^ Installation of a new suction accumulator is not necessary when repairing the air conditioning system except when there is physical evidence of system contamination from a failed A/C compressor or damage to the suction accumulator.

The evaporator core is the plate/fin type with a unique refrigerant flow path.
^ A mixture of refrigerant and oil enters the bottom of the evaporator core through the evaporator core inlet tube and is routed so it flows through the partitioned first three plate/fin sections.
^ The next four plate/fin sections are partitioned to force the refrigerant to flow toward the other end of the evaporator.
^ Refrigerant then continues over to the remaining five plate/fin sections and moves out of the evaporator core thought the evaporator core outlet tube.
^ This S-pass flow pattern accelerates the flow of refrigerant and oil though the evaporator core.

A/C Evaporator Core Orifice

NOTE: A new A/C evaporator core orifice should be installed whenever a new A/C compressor is installed.

The A/C evaporator core orifice:
^ is located in the A/C evaporator core inlet tube.
^ has an inlet filter screen that acts as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice.
^ evaporates the liquid refrigerant into gas and the exchange cools the vehicle interior.
^ has O-ring seals on the A/C evaporator core orifice that prevent the high-pressure liquid refrigerant from bypassing the A/C evaporator core orifice.
^ is not repairable and must be installed as a unit.

Suction Accumulator
Refrigerant enters the suction accumulator and the heavier, oil-laden refrigerant falls to the bottom of the suction accumulator canister. When the heavier liquid refrigerant and oil mixture enters the suction line, it has a second opportunity to vaporize and circulate through the A/C compressor without causing damage. A desiccant bag is mounted inside the suction accumulator to absorb any mixture in the refrigerant system.

A/C Cycling Switch
The A/C cycling switch is mounted on a Schrader valve-type fitting at the top of the suction accumulator/drier. The switch allows the pressure inside the suction accumulator/drier to control the operation of the switch.

A/C Pressure Cut-Off Switch
The A/C pressure cut-off switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.

The A/C pressure cut-off switch:
^ is located on a Schrader valve-type fitting on the high-pressure side of the A/C manifold and tube.
^ is a valve depressor, located inside the threaded end of the A/C pressure cut-off switch, and is used to monitor the compressor discharge pressure.
^ opens and disengages the A/C compressor whenever the discharge pressure rises to approximately 2,896 kPa (420 psi).
^ closes and engages the compressor whenever the pressure drops to approximately 1,724 kPa (250 psi).
^ can be removed without discharging the refrigerant from the system.

Spring Lock Coupling
The spring lock coupling is a refrigerant line coupling held together by a garter spring inside a circular cage.

Gauge Port Valves
The high-pressure gauge port valve is located on the A/C manifold and tube.

The low-pressure gauge port valve is located on the suction accumulator/drier.

The fitting is an integral part of the refrigeration line or component.