Air Conditioning
Component Locations:
Refrigeration System Components, Part 1:
Refrigeration System Components, Part 2:
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
- 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 cutoff 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.
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 A/C evaporator core inlet tube to meter the liquid refrigerant into the A/C evaporator core.
A/C Compressor and Clutch Assembly
NOTE:
- Internal A/C compressor components are not serviced separately. The FS-10 A/C compressor is serviced only as an assembly. The A/C clutch, A/C clutch pulley, A/C clutch field coil and the shaft seal are serviceable.
- Installation of a new 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 A/C compressor oil from vehicles equipped with an FS-10 A/C compressor may have a dark color while maintaining a normal oil viscosity. This is normal for this A/C compressor because carbon from the piston rings will discolor the oil.
The FS-10 A/C compressor has the following characteristics:
- a 10-cylinder swashplate design utilizing the tangential design mount
- a one-piece lip-type seal (installed from the front of the A/C compressor) which is used to seal it at the shaft opening in the assembly
- five double-acting pistons which operate within the cylinder assembly (The pistons are actuated by a swashplate that converts the rotating action of the shaft to a reciprocating force.)
- reed-type discharge valves located between the cylinder assembly and the head at each end of the A/C compressor
- uses PAG oil. This oil contains special additives required for the A/C compressor.
A/C Compressor Clutch Assembly:
The magnetic A/C clutch has the following characteristics:
- It drives the compressor shaft.
- When battery positive voltage (B+) is applied to the A/C clutch field coil, the clutch disc and hub assembly is drawn toward the A/C clutch pulley.
- The magnetic force locks the clutch disc and hub assembly and the A/C clutch pulley together as one unit, causing the compressor shaft to rotate.
- When B+ is removed from the A/C clutch field coil, springs in the clutch disc and hub assembly move the clutch disc away from the A/C clutch pulley.
A/C Compressor Pressure Relief Valve
An A/C compressor pressure relief valve is incorporated in the compressor A/C manifold and tube to:
- relieve unusually high refrigerant system discharge pressure buildups. For information regarding operating pressure specifications, refer to Specifications.
- prevent damage to the A/C compressor and other system components.
- avoid total refrigerant loss by closing after the excessive pressure has been relieved.
A/C Condenser Core
NOTE: Installation of a new 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 A/C condenser core has the following characteristics:
- It is an aluminum fin and tube design heat exchanger located in front of the vehicle radiator.
- It 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
NOTE: Installation of a new 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 condenser to evaporator tube contains high pressure liquid refrigerant upstream of the A/C evaporator core orifice.
The A/C compressor to condenser discharge line contains high pressure refrigerant gas. It has the following features:
- an integral non-serviceable muffler
- a fitting used to mount the A/C pressure cutoff switch. (A long-travel Schrader-type valve stem core is installed in the fitting so that the A/C pressure cutoff switch can be removed without discharging the A/C system.)
- a fitting used to mount a serviceable high-pressure A/C charge port valve
The A/C manifold and tube is attached to the A/C compressor, is sealed with O-ring seals, and has the following features:
- The upstream side contains low pressure refrigerant gas.
- The downstream side contains high pressure refrigerant gas and a port to mount the A/C compressor pressure relief valve.
The accumulator to compressor tube has a fitting used to mount the A/C cycling switch. A long-travel Schrader-type valve stem core is installed in the fitting so that the A/C cycling switch can be removed without discharging the A/C system.
A/C Evaporator Core
NOTE:
- The evaporator core is not separately serviceable. It is serviced only with the evaporator core housing assembly.
- Installation of a new 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 A/C evaporator core is the plate/fin type with a unique refrigerant flow path.
- A mixture of refrigerant and oil enters the bottom of the A/C evaporator core through the A/C evaporator core inlet tube and then moves out of the A/C evaporator core through the A/C evaporator core outlet tube.
- This flow pattern accelerates the flow of refrigerant and oil through the A/C 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 has the following characteristics:
- It is located in the A/C evaporator core inlet tube.
- It has filter screens located on the inlet and outlet ends of the tube body.
- The inlet filter screen acts as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice.
- O-ring seals on the A/C evaporator core orifice prevent the high-pressure liquid refrigerant from bypassing the A/C evaporator core orifice.
- Adjustment or service cannot be made to the A/C evaporator core orifice assembly. It must be installed as a unit.
Suction accumulator
NOTE: Installation of a new 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 suction accumulator is mounted to the right of the vehicle centerline. The inlet tube of the suction accumulator attaches directly to the A/C evaporator core outlet tube and the outlet tube of the suction accumulator attaches to the evaporator to compressor suction line.
After entering the inlet of the suction accumulator, heavier oil-laden refrigerant contacts an internally mounted dome (which serves as an umbrella) and drips down onto the bottom of the canister.
- A small diameter oil bleed hole, in the bottom of the vapor return tube, allows the accumulated heavier liquid refrigerant and oil mixture to re-enter the compressor suction line at a controlled rate.
- As the heavier mixture passes through the small diameter liquid bleed hole, it has a second chance to vaporize and recirculate through the A/C compressor without causing compressor damage due to slugging.
- A fine mesh screened filter fits tightly around the bottom of the vapor return tube to filter out refrigerant system contaminant particles.
- A desiccant bag is mounted inside the canister to absorb any moisture which may be in the refrigerant system.
- A fitting located on the side of the suction accumulator is used to mount a serviceable low-pressure A/C charge port valve.
A/C Cycling Switch
The A/C cycling switch is mounted on a Schrader valve-type fitting on the suction accumulator/driver.
- A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.
- This allows the suction or low side pressure to control the operation of the A/C cycling switch.
- The electrical switch contacts open when the suction pressure drops. The contacts close when the suction pressure rises.
- When the A/C cycling switch contacts close, the A/C clutch field coil is energized.
- When the A/C cycling switch contacts open, the A/C clutch field coil is de-energized and compressor operation stops.
- The A/C cycling switch will control the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing.
- This prevents icing of the A/C evaporator core and blockage of airflow.
- It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.
A/C Pressure Cutoff Switch
The A/C pressure cutoff switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.
- The A/C pressure cutoff switch is mounted on a Schrader valve-type fitting on the A/C compressor to condenser discharge line.
- It is not necessary to discharge the refrigerant system to remove the A/C pressure cutoff switch.
- A valve depressor, located inside the threaded end of the A/C pressure cutoff switch, presses on the Schrader valve stem.
- This allows the A/C pressure cutoff switch to monitor the compressor discharge pressure.
- When the compressor discharge pressure rises, the switch contacts open, disengaging the A/C compressor. When the pressure drops, the contacts close to allow operation of the A/C compressor. For information regarding operating pressure specifications, refer to Specifications.
The switch contains a second set of electrical contacts used for high-speed cooling fan control.
- When the compressor discharge pressure rises, the contacts close and engage the high-speed fan control. When the pressure drops, the contacts open and the high speed fan control is disengaged.
Spring Lock Coupling:
Spring Lock Coupling
The spring lock coupling is a refrigerant line coupling held together by a garter spring inside a circular cage.
- When the coupling is connected together, the flared end of the female fitting slips behind the garter spring inside the cage of the male fitting.
- The garter spring and cage then prevent the flared end of the female fitting from pulling out of the cage.
- Three O-ring seals are used to seal between the two halves of the A/C condenser core couplings, all other couplings have two O-ring seals.
- Use only the O-ring seals listed in the Ford Master Parts Catalog for the spring lock coupling.
- A plastic indicator ring is used on the spring lock couplings of the A/C evaporator core to indicate, during vehicle assembly, that the coupling is connected. Once the coupling is connected, the indicator ring is no longer necessary but will remain captive by the coupling near the cage opening.
- The indicator ring may also be used during service operations to indicate connection of the coupling.
- An A/C tube lock coupling clip may be used to secure the coupling but is not required.
Peanut Fitting
The A/C condenser core uses the peanut-shaped refrigerant fittings instead of spring lock couplings.
- The male and female blocks of the peanut fitting are retained with a nut.
- An O-ring seal is installed around the tube on the male block.
- The female block is welded to the tube and is not adjustable.
- Support the female fitting with a wrench to prevent twisting of the tubes.
- The male block will pivot around the tube to allow for alignment with the female block during assembly.
- When properly assembled the male and female fittings should be flush.
- Use only the O-ring seals listed in the Ford Master Parts Catalog for the peanut fitting.
Service Gauge Port Values:
Service Gauge Port Valves
The high-pressure service gauge port valve is located on the front A/C manifold and tube.
The low pressure service gauge port valve is located on the suction accumulator.
The fitting is an integral part of the refrigeration line or component.
- Special couplings are required for both the high side and low side service gauge ports.
- A new Schrader-type valve core can be installed if the seal leaks.
- Always install the A/C charging valve cap on the service gauge port valves after repairing the refrigerant system.