Refrigerant System

The manual A/C-heater refrigerant system uses the following components:

• A/C compressor (19703).
• A/C condenser core (19712).
• A/C evaporator core (19860).
• A/C evaporator core orifice (19D990) in the condenser to evaporator tube (19835) near the A/C condenser core .
• A/C cyclic switch (19E561).
• Service access gauge port valves.
• And the necessary refrigerant lines for the system.

Service Access Gauge Port Valves

The refrigerant system has a high-pressure (discharge) and a low-pressure (suction) gauge port valve. The quick disconnects (Rotunda 176-R0026 R134a Low Side Quick Disconnect and 176-R0027 R-134a High Side Quick Disconnect or equivalents) must be used to make the manifold gauge set work.

Always replace the A/C charging valve caps (19D702) on the service access gauge port valves after servicing the refrigerant system.

A/C Evaporator Core

NOTE: Replacement of the suction accumulator/drier 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/drier.

The A/C evaporator core has the following features:

• It is a multi-pass plate/fin-type mounted in a vertical position.
• Vaporized refrigerant enters the A/C evaporator core at the lower corner and flows through the first three plate/fin sections to the other end.
• The refrigerant then reverses and flows through the next three plate/fin sections to the opposite end; there, the flow again reverses and flows through the remaining four plate/fin sections to the condenser to evaporator tube .
• This S-pass flow pattern accelerates the flow of refrigerant through the A/C evaporator core which does not have a liquid bleed line.
• The multi-pass A/C evaporator core can be identified by a paint spot on the condenser to evaporator tube , a blue shipping cap and folded-down locator tabs.

A/C Evaporator Core Orifice

The A/C evaporator core orifice assembly has the following features:

• It provides a restriction between the high and low pressure liquid refrigerant.
• It meters the flow of liquid refrigerant into the A/C evaporator core .
• A/C evaporator core temperature is controlled by sensing the pressure within the A/C evaporator core with a pressure-operated electric switch.
• The A/C cyclic switch controls A/C compressor operation as necessary to maintain the A/C evaporator core pressure within specified limits.

• The A/C evaporator core orifice is located in the condenser to evaporator tube near the A/C compressor .
• It has filter screens located on the inlet and outlet ends of the tube body. The filter screens act as a strainer for the liquid refrigerant flowing through the A/C evaporator core orifice opening.
• O-ring seals (9229), on the tube body, prevent the high pressure liquid refrigerant from bypassing the A/C evaporator core orifice .
• Adjustment or services cannot be made to the A/C evaporator core orifice assembly.
• It must be replaced as a unit.

Suction Accumulator/Drier

The suction accumulator/drier has the following features:

• It is mounted to the engine side of the dash panel (01610) on the right side of the vehicle.
• The inlet tube of the suction accumulator/drier attaches directly to the A/C evaporator core outlet tube.
• Refrigerant enters the suction accumulator/drier canister through the inlet tube and the heavier oil-laden refrigerant falls to the bottom of the canister. A small-diameter oil bleed hole is located in the side of the outlet tube near the bottom of the canister. This bleed hole is covered with a filter and allows a small amount of the heavier liquid refrigerant and oil mixture to re-enter the suction line at a controlled rate.
• 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 to the A/C compressor due to refrigerant slugging.

• A desiccant bag is mounted inside the suction accumulator/drier canister to absorb any moisture which may be in the refrigerant system.
• A fitting located on the top of the canister is used to attach the A/C cyclic switch . A long-travel Schrader-type valve stem core is installed in the fitting opening to prevent refrigerant loss when the A/C cyclic switch is removed.

A/C Cyclic Switch

The A/C cyclic switch has the following features:

• It is mounted on a Schrader valve-type fitting on the top of the suction accumulator/drier assembly.
• A valve depressor, located inside the threaded end of the A/C cyclic switch , presses in on the Schrader valve stem as the A/C cyclic switch is mounted.
• This allows the suction pressure inside the suction accumulator/drier canister to control A/C cyclic switch operation.
• The switch contacts are normally open when the suction pressure is approximately 152-193 kPa (22-28 psi); switch contacts close when the suction pressure rises to approximately 276-324 kPa (40-47 psi) or above.
• Lower ambient temperatures (below approximately 10°C or 50°F) will also open the A/C cyclic switch contacts due to the pressure/temperature relationship of the refrigerant in the system.
• The A/C cyclic switch contacts control the electrical circuit to the A/C compressor clutch field coil (2987) .
  • When the electrical switch contacts are closed, the A/C compressor clutch field coil is energized and the A/C clutch (2884) is engaged to drive the A/C compressor .
  • When the switch contacts are open, the A/C compressor clutch field coil is de-energized, the A/C clutch is disengaged and the A/C compressor does not operate.
• The A/C cyclic switch controls the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing. This prevents A/C evaporator core from icing and the blockage of airflow.

A/C Condenser Core

The A/C condenser core has the following features:

• It is an aluminum fin and tube design heat exchanger.
• It is located in front of the vehicle radiator (8005) .
• It cools compressed refrigerant gas by allowing air to pass over the fins and tubes to extract the heat and condenses the gas to liquid refrigerant as it is cooled.
• The A/C condenser core inlet and outlet connections are the male part of a spring lock coupling.
• A special service tool is required to disconnect the refrigerant lines from the A/C condenser core.

A/C Compressor

The A/C compressor has the following features:

• It is Ford built.
• It has a displacement of 170cc (10.4 cubic inch).
• It is lubricated by a charge of Motorcraft YN-12 or equivalent refrigerant oil in the refrigerant system.

• The A/C manifold and tube (19D734) is mounted on the rear face of the A/C compressor and secured by a single bolt.
• The A/C compressor pressure relief valve is located in the A/C compressor to condenser discharge line (19972) .

NOTE: Whenever an A/C compressor is replaced, it will be necessary to replace the suction accumulator/drier and perform a filtering procedure.

Spring Lock Coupling

The spring lock coupling, shown in a disconnected state, is a refrigerant line coupling held together by a garter spring inside a circular cage. When the coupling is connected, 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.

• Two O-ring seals are used to seal between the two halves of the coupling. These O-ring seals are made of special green material and must be replaced with an O-ring seal made of the same green material. The O-ring seals normally used in refrigerant system connections are not the same material and should not be used with the spring lock coupling. 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 spring lock couplings 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. After the coupling has been cleaned, new green O-ring seals should be lubricated with clean refrigerant and installed. Insert the tabs of the indicator ring into the cage opening. Then connect the coupling together by pushing with a slight twisting motion. When the coupling is connected, the indicator ring will snap out of the cage opening but will remain captured on the coupling by the refrigerant line.

*Also supplied in Kit E35Y-19D690-D with Garter Springs.

**Also supplied in Kit E35Y-19D690-D with Garter Springs and in Kit E177-19B596-A.

A/C Compressor Pressure Relief Valve

• An A/C compressor pressure relief valve is installed on the A/C compressor to relieve excessive high-pressure buildup (3103 kPa or 450 psi and above) and prevent damage to the A/C compressor and other A/C components.
• The A/C compressor pressure relief valve is located on the discharge side of the (high pressure) A/C manifold and tube .

A/C Pressure Cut-Off Switch

The A/C pressure cut-off switch (19D594) is located in the discharge line between the A/C compressor and A/C condenser core .

The A/C pressure cut-off switch has two sets of contacts. One electrical contact is normally closed. When compressor head pressure rises to approximately 2896 kPa (420 psi), the contacts open and the compressor operation is shut off. When head pressure drops to approximately 1724 kPa (250 psi), the contacts again close and allow operation of the A/C compressor . Shutting down compressor operation prior to the pressure relief valve set point ensures containment of the refrigerant in the A/C system.

The switch contains a second set of electrical contacts for the high speed cooling fan which are normally open. When discharge line pressure reaches approximately 2241 kPa (325 psi), these contacts close and engage the high speed radiator electric motor. When pressure drops to approximately 1896 kPa (275 psi), the contacts again open and the high speed radiator electric motor is disengaged.