description and operation · the condenser core, being close to ambient humidity) to turn to ice....

412-00-1 412-00-1Climate Control System - General Information

DESCRIPTION AND OPERATION

• Charge the A/C system with the engineClimate Control Systemrunning only at the low-pressure side to

WARNING: To avoid accidental prevent refrigerant slugging from damaging thedeployment and possible injury, the air bag A/C compressor.system backup power supply must be depleted

• Use only R-134a refrigerant. Due tobefore repairing any climate control components.environmental concerns, when the airTo deplete the backup power supply, disconnectconditioning system is drained, the refrigerantthe battery negative cable and wait one minute.must be collected using refrigerant

WARNING: Carbon monoxide is colorless, recovery/recycling equipment. Federal lawodorless and dangerous. If it is necessary to REQUIRES that R-134a be recovered intooperate the engine with the vehicle in a closed appropriate recovery equipment and thearea such as a garage, always use an exhaust process be conducted by qualified technicianscollector to vent the exhaust gases outside the who have been certified by an approvedclosed area. organization, such as MACS, ASI, etc. Use of a

recovery machine dedicated to R-134a isWARNING: R-134a is classified as a safenecessary to reduce the possibility of oil andrefrigerant, but misuse can make it dangerous.refrigerant incompatibility concerns. Refer toThe following precautions must be observed.the instructions provided by the equipment

• Always wear safety goggles when repairing an manufacturer when removing refrigerant fromair conditioning system. or charging the air conditioning system.

• Avoid contact with liquid refrigerant R-134a. • Refrigerant R-134a must not be mixed with airR-134a vaporizes at approximately -25°C for leak testing or used with air for any other(-13°F) under atmospheric pressure and it will purpose above atmospheric pressure. R-134a isfreeze skin tissue. combustible when mixed with high

concentrations of air and higher pressures.• Never allow refrigerant R-134a gas to escape inquantity in an occupied space. R-134a is • A number of manufacturers are producingnon-toxic, but it will displace the oxygen refrigerant products that are described asneeded to support life. direct substitutes for Refrigerant R-134a. The

use of any unauthorized substitute refrigerant• Do not allow any portion of the charged aircan severely damage the A/C components. Ifconditioning system to become too hot. Therepair is required, use only new or recycledpressure in an air conditioning system rises asRefrigerant R-134a.the temperature rises and temperatures of

approximately 85°C (185°F) can be dangerous. CAUTION: To avoid contaminations of the• Allow the engine to cool sufficiently prior to A/C system:

carrying out maintenance or serious burns and• Never open or loosen a connection beforeinjury can occur.

discharging the system.CAUTION: To avoid damaging the vehicle • When loosening a connection, if any residual

or A/C components, the following precautions pressure is evident, allow it to leak out beforemust be observed.

opening the fitting.• The A/C refrigerant of all vehicles must be • Evacuate a system that has been opened to

identified and analyzed prior to refrigerant install a new component or one that hascharging. Failure to do so can contaminate the discharged through leakage before charging.shop bulk refrigerant and other vehicles.

• Seal open fitting with a cap or plug• Do not add R-12 refrigerant to an A/C system immediately after disconnecting a component

that requires the use of R-134a refrigerant. from the system.These two types of refrigerant must never be

• Clean the outside of the fittings thoroughlymixed. Doing so can damage the A/C system.before disconnecting a component from thesystem.

Copyright 2002, Ford Motor CompanyLast updated: 7/22/2002 2003 Taurus/Sable, 8/2002


DESCRIPTION AND OPERATION (Continued)

Principles of Operation• Do not remove the sealing caps from a newcomponent until ready to install. There are four main principles involved with the

basic theory of operation:• Refrigerant oil will absorb moisture from theatmosphere if left uncapped. Do not open an • heat transferoil container until ready to use and install the

• latent heat of vaporizationcap immediately after using. Store the oil in aclean, moisture-free container. • relative humidity

• Install a new O-ring seal before connecting an • effect of pressureopen fitting. Coat the fitting and O-ring seal

Heat Transferwith refrigerant oil before connecting.If two substances of different temperature are placed• When installing a refrigerant line, avoid sharpnear each other, the heat in the warmer substancebends. Position the line away from the exhaustwill transfer to the colder substance.or any sharp edges that can chafe the line.

• Tighten threaded fittings only to specifications. Latent Heat of VaporizationThe steel and aluminum fittings used in the When a liquid boils (converts to gas) it absorbs heatrefrigerant system will not tolerate without raising the temperature of the resulting gas.over-tightening. When the gas condenses (converts back to a liquid),

• When disconnecting a fitting, use a wrench on it gives off heat without lowering the temperature ofboth halves of the fitting to prevent twisting of the resulting liquid.the refrigerant lines or tubes.

Relative Humidity• Do not open a refrigerant system or uncap aThe amount of moisture (water vapor content) thatnew component unless it is as close as possiblethe air can hold is directly related to the airto room temperature. This will preventtemperature. The more heat there is in the air, thecondensation from forming inside a componentmore moisture the air can hold. The lower thethat is cooler than the surrounding air.moisture content in the air, the more comfortableThe manual climate control system heats or coolsyou feel. Removing moisture from the air lowers itsthe vehicle depending on the function selectorrelative humidity and improves personal comfort.switch (19B888) position and the temperature

selected. Effects of Pressure on Boiling orCondensation• The function selector switch position determinesAs the pressure is increased on a liquid, theheating or cooling and air distribution.temperature at which the liquid boils (converts to• The temperature control setting determines the airgas) also increases. Conversely, when the pressuretemperature.on a liquid is reduced, its boiling point is also

• The blower motor switch (18578) varies the reduced. When in the gas state, an increase inblower motor speed. pressure causes an increase in temperature, while a

The electronic automatic temperature control decrease in pressure will decrease the temperature(EATC) system maintains the selected vehicle of the gas.interior temperature by heating or cooling the air.

Compressor Anti-Slugging Strategy• During A/C operation the system also reduces the (CASS)

relative humidity of the air. Liquid refrigerant may accumulate in the A/C• The driver may override the automatic mode of compressor under certain conditions. To alleviate

operation. damage to the A/C compressor, the compressoranti-slugging strategy (CASS) is utilized.

2003 Taurus/Sable, 8/2002



CASS is initiated only under specific conditions: The liquid refrigerant is now at its lowest pressureand temperature. As it passes through the evaporator

• the ignition is off for more than 8 hours core (19860), it absorbs heat from the passenger• the ambient temperature is above -4°C (25°F) compartment airflow passing over the plate/fin

sections of the evaporator core. This addition of• battery voltage is above 8.5 volts during engineheat causes the refrigerant to boil (convert to gas).crankingThe now cooler passenger compartment air can noWhen these conditions are present, the powertrainlonger support the same humidity level of thecontrol module (PCM) will activate the A/C controlwarmer air and this excess moisture condenses onrelay prior to the engine cranking. The A/C controlthe exterior of the evaporator coils and fins andrelay engages the A/C compressor for approximatelydrains outside the vehicle.4-15 revolutions of the A/C compressor or aThe suction accumulator (19C836) is designed tomaximum of 2 seconds (depending upon vehicleremove moisture from the refrigerant and to preventapplication), allowing the liquid refrigerant to beany liquid refrigerant that may not have beenpushed from the A/C compressor. CASS is initiatedvaporized in the evaporator core from reaching theby the PCM regardless of the function selectorA/C compressor. The A/C compressor is designedswitch position.to pump refrigerant vapor only, as liquid refrigerant

The Refrigerant Cycle will not compress and can damage the A/Ccompressor.During stabilized conditions (air conditioning system

shutdown), the refrigerant is in a vaporized state The refrigerant cycle is now repeated with the A/Cand pressures are equal throughout the system. compressor again, increasing the pressure andWhen the A/C compressor (19703) is in operation it temperature of the refrigerant.increases pressure on the refrigerant vapor raising The evaporator air discharge temperature sensorits temperature. The high-pressure and (19C734) interrupts compressor operation before thehigh-temperature vapor is then released into the top external temperature of the evaporator core gets lowof the condenser core (19712). enough to cause the condensed water vapor (excessThe condenser core, being close to ambient humidity) to turn to ice.temperature, causes the refrigerant vapor to The high-side line pressure is monitored so that A/Ccondense into a liquid when heat is removed from compressor operation can be interrupted if systemthe refrigerant by ambient air passing over the fins pressure becomes too high.and tubing. The now liquid refrigerant, still at high

The low-side line pressure is monitored by the lowpressure, exits from the bottom of the condensercharge switch (19E561) which disengages the A/Ccore and enters the inlet side of the evaporator corecompressor if the system pressure becomes too loworifice (19D990).due to a low refrigerant charge.

The evaporator core orifice is the restriction in theThe A/C pressure relief valve (19D644) will openrefrigerant system that creates the high-pressureand vent refrigerant to relieve unusually high systembuildup upstream of the condenser core andpressure.separates the high and low pressure sides of the A/C

system. As the liquid refrigerant leaves thisrestriction, its pressure and boiling point arereduced.




Clutch Cycling Orifice Tube Type Refrigerant System




• The A/C compressor will operate if the outsideItem Part Number Descriptiontemperature is above approximately 6°C (43°F).1 19D701 A/C charge valve port (low

side) • The blower motor is on.2 19E561 Low charge protection switch

A/C3 19C836 Suction accumulator/drier

4 19703 A/C compressor

5 19D644 A/C pressure relief valve

6 19D594 Pressure cutoff switch

7 19D701 A/C charge valve port (highside)

8 19712 Condenser core

9 19D990 Evaporator core orifice

10 19860 Evaporator core

11 — Low pressure vapor

12 — High pressure vapor

13 — Low pressure liquid

14 — High pressure liquid When A/C is selected:

• The air inlet door vacuum control motor is at noSystem Airflow Description — Manualvacuum, admitting only outside air into theClimate Controlpassenger compartment.

MAX A/C • The defrost door and floor console duct door (ifequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at no vacuum, directing airflow to theinstrument panel A/C registers and the centerconsole registers (if equipped). A small amountof airflow from the side window demisters will bepresent.

• Blended air temperature is available.

• The A/C compressor will operate if the outsidetemperature is above approximately 6°C (43°F).

• The blower motor is on.

PANELWhen MAX A/C is selected:

• The air inlet door vacuum control motor is at fullvacuum, closing off outside air and admitting onlyrecirculated air.

• The defrost door and floor console duct door (ifequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at no vacuum, directing airflow to theinstrument panel A/C registers and the centerconsole registers (if equipped). A small amountof airflow from the side window demisters will bepresent.

• Blended air temperature is available.




PANEL/FLOORWhen PANEL is selected:

• The air inlet door vacuum control motor is at novacuum, admitting only outside air into thepassenger compartment.

• The defrost door and floor console duct door (ifequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at no vacuum, directing airflow to theinstrument panel A/C registers and the centerconsole registers (if equipped). A small amountof airflow from the side window demisters will bepresent.

• The temperature can be adjusted to heat the air,but the air cannot be cooled below the outside When PANEL/FLOOR is selected:temperature.

• The air inlet door vacuum control motor is at no• The A/C compressor will not operate. vacuum, admitting only outside air into the

passenger compartment.• The blower motor is on.

• The defrost door and floor console duct door (ifOFFequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at partial vacuum, directing airflow tothe floor duct, the instrument panel A/C registersand the center console registers (if equipped). Asmall amount of airflow from the side windowdemisters will be present.



FLOOR

When OFF is selected:

• The air inlet door vacuum control motor is at fullvacuum, closing off outside air from entering thepassenger compartment.

• The defrost door and floor console door (ifequipped) vacuum control motors are at novacuum, and the panel/floor door vacuum controlmotor is at full vacuum, closing off airflow to thedefrost duct, side window demisters, floor duct,instrument panel A/C registers and center consoleregisters (if equipped).

When FLOOR is selected:• The A/C compressor will not operate.

• The air inlet door vacuum control motor is at no• The blower motor is off.vacuum, admitting only outside air into thepassenger compartment.




DEFROST• The panel/floor door vacuum control motor is atfull vacuum and the defrost door and floorconsole duct door (if equipped) vacuum controlmotors are at no vacuum, directing airflow to thefloor duct.

• The temperature can be adjusted to heat the air,but the air cannot be cooled below the outsidetemperature.

• The A/C compressor will not operate.


FLOOR/DEFROST

When DEFROST is selected:


• The panel/floor door, defrost door and floorconsole duct door (if equipped) vacuum controlmotors are at no vacuum, directing airflow to thedefroster duct and the side window demisters.

• The temperature can be adjusted to heat or coolthe air below the outside temperature.

• The A/C compressor will operate if the outsideWhen FLOOR/DEFROST is selected:temperature is above approximately 6°C (43°F).

• The air inlet door vacuum control motor is at no• The blower motor is on.vacuum, admitting only outside air into the

passenger compartment. System Airflow Description — ElectronicAutomatic Temperature Control• The panel/floor door vacuum control motor is at

partial vacuum and the defrost door and floorAUTOconsole duct door (if equipped) vacuum controlWhen AUTO is selected:motors are at no vacuum, directing airflow to the

floor duct, the defroster duct and the side window • The temperature control setting is manually set todemisters. the desired settings.

• The temperature can be adjusted to heat or cool • The air inlet door vacuum control motor isthe air below the outside temperature. automatically controlled by the EATC module,

• The A/C compressor will operate if the outside based on the temperature setting.temperature is above approximately 6°C (43°F). • The mode door vacuum control motors are

• The blower motor is on. automatically controlled by the EATC modulebased on the temperature setting.

• The A/C compressor is automatically controlledby the EATC module based on the temperaturesetting. The A/C compressor will not operate ifthe outside temperature is lower thanapproximately 6°C (43°F).




• The blower motor is on. The blower motor speed When PANEL is selected:is automatically controlled by the EATC module

• The air inlet door vacuum control motor is at nobased on the temperature setting, but can bevacuum, admitting only outside air into themanually overridden.passenger compartment.

OFF • The defrost door and floor console duct door (ifequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at no vacuum, directing airflow to theinstrument panel A/C registers and the centerconsole registers (if equipped).

• The temperature can be adjusted to heat the air,but the air cannot be cooled below the outsidetemperature.

• The A/C compressor will not operate.


PANEL/FLOOR

When OFF is selected:

• The air inlet door vacuum control motor is at fullvacuum, closing off outside air from entering thepassenger compartment.

• The defrost door and floor console door (ifequipped) vacuum control motors are at novacuum, and the panel/floor door vacuum controlmotor is at full vacuum, closing off airflow to thedefrost duct, side window demisters, floor duct,instrument panel A/C registers and center consoleregisters (if equipped).

• The A/C compressor will not operate.When PANEL/FLOOR is selected:

• The blower motor is OFF.• The air inlet door vacuum control motor is at no

PANEL vacuum, admitting only outside air into thepassenger compartment.

• The defrost door and floor console duct door (ifequipped) vacuum control motors are at fullvacuum and the panel/floor door vacuum controlmotor is at partial vacuum, directing airflow tothe instrument panel A/C registers, the floor ductand the center console registers (if equipped).







FLOOR • The panel/floor door vacuum control motor is atpartial vacuum and the defrost door and floorconsole duct door (if equipped) vacuum controlmotors are at no vacuum, directing airflow to thefloor duct, the defroster duct and the side windowdemisters.




DEFROST

When FLOOR is selected:


• The panel/floor door vacuum control motor is atfull vacuum and the defrost door and floorconsole duct door (if equipped) vacuum controlmotors are at no vacuum, directing airflow to thefloor duct.


• The A/C compressor will operate if the outside When DEFROST is selected:temperature is above approximately 6°C (43°F).

• The air inlet door vacuum control motor is at no• The blower motor is on. vacuum, admitting only outside air into the

passenger compartment.FLOOR/DEFROST• The panel/floor door, defrost door and floor

console duct door (if equipped) vacuum controlmotors are at no vacuum, directing airflow to thedefrost duct and the side window demisters.




When FLOOR/DEFROST is selected:





Manual Climate Control System Electrical Components

Item Part Number Description Item Part Number Description

8 19703 A/C compressor1 18C864 Climate control assembly —integrated control panel (ICP) 9 12A648 Engine coolant temperature

sensor (CTS)2 19E561 Low charge protection switch

10 19805 Blower motor3 19D594 Pressure cutoff switch

11 19C734 Evaporator air discharge4 9E731 Vehicle speed sensor (VSS)temperature sensor5 6C315 Crankshaft position sensor

12 14B192 Blower motor relay(CKP)

13 19A706 Blower motor resistor6 14B192 A/C control relay(Continued)7 9B989 Throttle position sensor (TPS)

(Continued)





14 19E616 Temperature blend door 15 12A650 Powertrain control moduleactuator (PCM)

(Continued)

Electronic Automatic Temperature Control System Electrical Components


4 14B192 Blower motor relay1 18C858 Climate control assembly —integrated control panel (ICP) 5 19E561 Low charge protection switch

2 19E624 Blower motor speed control 6 19D594 Pressure cutoff switch3 19805 Blower motor 7 9E731 Vehicle speed sensor (VSS)

(Continued) (Continued)





8 6C315 Crankshaft position sensor 15 19E702 Ambient air temperature(CKP) sensor

9 19C734 Evaporator air discharge 16 14A597 Solar amplifier (sunloadtemperature sensor sensor)

10 19703 A/C compressor 17 19C734 In-car temperature sensor

11 12A650 Powertrain control module 18 19E616 Temperature blend door(PCM) actuator

12 14B192 A/C control relay 19 18C612 Remote climate control(RCC) module13 9B989 Throttle position sensor (TPS)

14 12A648 Engine coolant temperaturesensor (CTS)

(Continued)


description and operation · the condenser core, being close to ambient humidity) to turn to ice....

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