Climate Control System-General Information: Other Ford Thunderbird XI

Heat Transfer

If two substances of different temperature are placed near each other, the heat in the warmer substance will transfer to the colder substance.

Latent Heat of Vaporization

When a liquid boils (converts to gas) it absorbs heat without raising the temperature of the resulting gas. When the gas condenses (converts back to a liquid), it gives off heat without lowering the temperature of the resulting liquid.

Relative Humidity

The amount of moisture (water vapor content) that the air can hold is directly related to the air temperature. The more heat there is in the air, the more moisture the air can hold. The lower the moisture content in the air, the more comfortable you feel. Removing moisture from the air lowers it s relative humidity and improves personal comfort.

Effects of Pressure on Boiling or Condensation

As the pressure is increased on a liquid, the temperature at which the liquid boils (converts to gas) also increases. Conversely, when the pressure on a liquid is reduced, its boiling point is also reduced. When in the gas state, an increase in pressure causes an increase in temperature, while a decrease in pressure will decrease the temperature of the gas.

The Refrigerant Cycle

During stabilized conditions (air conditioning system shutdown), the refrigerant is in a vaporized state and pressures are equal throughout the system. When the A/C compressor is in operation it increases pressure on the refrigerant vapor, raising its temperature. The high-pressure and high-temperature vapor is then released into the top of the A/C condenser core.

The A/C condenser, being close to ambient temperature, causes the refrigerant vapor to condense into a liquid when heat is removed from the refrigerant by ambient air passing over the fins and tubing. The now liquid refrigerant, still at high pressure, exits from the bottom of the A/C condenser and enters the inlet side of the A/C receiver/drier. The receiver/drier is designed to remove moisture from the refrigerant.

The outlet of the receiver/drier is connected to the thermostatic expansion valve (TXV). The TXV provides the orifice which is the restriction in the refrigerant system and separates the high and low pressure sides of the A/C system. As the liquid refrigerant passes across this restriction, its pressure and boiling point are reduced.

The liquid refrigerant is now at its lowest pressure and temperature. As it passes through the A/C evaporator, it absorbs heat from the airflow passing over the plate/fin sections of the A/C evaporator. This addition of heat causes the refrigerant to boil (convert to gas). The now cooler air can no longer support the same humidity level of the warmer air and this excess moisture condenses on the exterior of the evaporator coils and fins and drains outside the vehicle.

The refrigerant cycle is now repeated with the A/C compressor again increasing the pressure and temperature of the refrigerant.

A thermistor which monitors the temperature of the air that has passed through the evaporator core controls A/C clutch cycling. If the temperature of the evaporator core discharge air is low enough to cause the condensed water vapor to freeze, the A/C clutch is disengaged by the vehicle powertrain control module (PCM).

The high-side line pressure is also monitored so that A/C compressor operation will be interrupted if the system pressure becomes too high or is determined to be too low (low charge condition).

The A/C compressor thermal protection switch will interrupt compressor operation if the compressor housing exceeds temperature limits.

The A/C compressor relief valve will open and vent refrigerant to relieve unusually high system pressure.

Scheme 113

A/C Evaporator Discharge Temperature Sensor

A/C EVAPORATOR DISCHARGE TEMPERATURE SENSOR Temperature Resistance -40°C (-40°F) 832,500-1,017,500 ohms -20°C (-4°F) 263,100-290,800 ohms 0°C (32°F) 91,050-100,600 ohms 20°C (68°F) 35,500-39,000 ohms 25°C (77°F) 28,500-31,500 ohms 40°C (104°F) 15,300-16,900 ohms 60°C (140°F) 7,170-7,930 ohms 100°C (212°F) 1,975-2,185 ohms -20°C (248°F) 1,130-1,250 ohms

Scheme 114

Coolant Control Valve

COOLANT CONTROL VALVE SPECIFICATION Coolant Control Valve Pins Resistance 1 and 2 10-23 ohms 2 and 3 10-23 ohms

Scheme 115

Heater Core

1. Inspect for evidence of coolant leakage at the heater hose to heater core attachments. A coolant leak in the heater hose could follow the heater core tube to the heater core and appear as a leak in the heater core.
2. Check the integrity of the heater hose clamps.

Heater Core-Plugged

1. Check to see that the engine coolant is at the correct level.
2. Start the engine and turn on the heater.
3. When the engine coolant reaches operating temperature, feel the heater core inlet and outlet hose to see if they are hot.
4. If the outlet only is not hot: the heater core may have an air pocket. the heater core may be plugged.
5. If the inlet only is not hot: the thermostat may not be working correctly. The coolant control valve may not be working correctly.

Air Conditioning (A/C) System Check - Retail Procedure

Note. This Retail Procedure is not eligible for claiming on Ford paid repairs (warranty and ESP).

Note. The engine should be run at idle for 10 minutes with the air conditioning on and set to MAX A/C before carrying out this retail procedure.

Note. Read and follow all of the Warnings, Cautions and Notes before continuing.

Material

MATERIAL SPECIFICATION

Disconnect

Scheme 116

1. Depressurize the engine cooling system.
2. Push the heater hose toward the tube to fully expose the locking tabs.
3. Push the special tool over the coupling retainer windows to compress the retainer locking tabs.
4. Pull the heater hose away from the heater core tube.
5. Spread the retainer tabs apart and slide the retainer off the tube. Discard the retainer.

Scheme 117

Scheme 118

1. Clean the tubes and lubricate with coolant hose lubricant or plain water.
2. Install a new coupling retainer (18D434) into the heater hose coupling housing.
3. Push the heater hose coupling onto the tube.
4. Make sure the heater hose coupling is fully engaged by lightly pulling on the heater hose.

Scheme 119

Procedure 1 - Ambient Temperature At or Below 38°C (100°F)

Note. The system performance can be evaluated and diagnosed by analysis of the compressor suction and discharge pressures. The following procedure is used to determine if the system is operating at normal pressures.

Note. The procedure varies depending on the ambient (shop) temperature. If the ambient temperature is 38°C (100°F) or lower, follow procedure 1. If the ambient temperature is over 38°C (100°F), follow procedure 2.

Note. If the A/C compressor cycles at any time during this test, refer to the DIAGNOSTIC TABLE .

Scheme 120

Scheme 121

1. Drive the vehicle or run the engine until it reaches normal operating temperature.
2. Connect a manifold gauge set or refrigerant service center with high-pressure and low-pressure gauges to the refrigerant system.
3. Set the climate controls. If equipped with manual climate control, set the A/C controls for normal A/C-PANEL mode, full COOL temperature, FRESH air, HI Blower. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON. If equipped with ATC, set temperature to 60°F (15°C) (lowest possible temp setting) with the dual function disabled (if equipped). Manually set blower on high. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON. If the vehicle is equipped with auxiliary climate control, set the auxiliary controls to full COOL in the PANEL mode at HI blower speed.
4. Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).
5. Confirm the compressor clutch is engaged and the engine cooling fan(s) are operating or engaged. Allow the vehicle to idle until the suction (low-side) and discharge (high-side) pressures are stable or fluctuate in a range that repeats.
6. Record the ambient (shop) temperature.
7. Record the discharge pressure. If the pressure is fluctuating, record the average value.
8. Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures chart.
9. Record the suction pressure. If the pressure is fluctuating, record the average value.
10. Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures chart.
11. Proceed to the diagnostic table.

Procedure 2 - Ambient Temperature Above 38°C (100°F)

Note. The system performance can be evaluated and diagnosed by analysis of the compressor suction and discharge pressures. The following procedure is used to determine if the system is operating at normal pressures.

Note. The procedure varies depending on the ambient (shop) temperature. If the ambient temperature is 38°C (100°F) or lower, follow procedure 1. If the ambient temperature is over 38°C (100°F), follow procedure 2.

Scheme 122

Scheme 123

1. Drive the vehicle or run the engine until it reaches normal operating temperature.
2. Connect a manifold gauge set or refrigerant service center with high-pressure and low-pressure gauges to the refrigerant system.
3. Set the climate controls. If equipped with manual climate control, set the A/C controls for normal A/C-PANEL mode, full COOL temperature, FRESH air, MED LO blower. If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON. If equipped with ATC, set temperature to 60°F (15°C) (lowest possible temp setting). Manually set blower to MED LO (3 to 4 bars). If the vehicle has a fresh air/recirc button, set it to FRESH. If the vehicle has an A/C switch or compressor on switch, set it to A/C ON. If the vehicle is equipped with auxiliary climate control, set the auxiliary controls to full COOL in the PANEL mode at MED LO blower speed.
4. Open all vehicle windows and leave the hood open for the test. Open the rear hatch and/or rear doors (if equipped).
5. Confirm the compressor clutch is engaged and the engine cooling fan(s) are operating or engaged. Allow the vehicle to idle until the suction (low-side) and discharge (high-side) pressures are stable or fluctuate in a range that repeats.
6. Record the ambient (shop) temperature.
7. Record the discharge pressure. If the pressure is fluctuating, record the average value.
8. Determine if the discharge pressure falls within the normal operating limits using the Normal Refrigerant Discharge Pressures chart.
9. Record the suction pressure. If the pressure is fluctuating, record the average value.
10. Determine if the suction pressure falls between normal operating limits using the Normal Refrigerant Suction Pressures chart.
11. Proceed to the diagnostic table.

Procedure

Scheme 124

1. Leak test the refrigerant system using the Refrigerant Leak Detector. Follow the instructions included with the leak detector for handling and operation techniques.
2. If a leak is found, discharge and recover the refrigerant. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) . Repair the system. Test the system for normal operation.

Scheme 125

Fluorescent Dye Detection

Note. Ford Motor Company vehicles are produced with R-134a fluorescent dye installed in the refrigerant system from the factory. The location of leaks can be pinpointed by the bright yellow-green glow of the fluorescent dye under a UV lamp. Since more than one leak can exist, make sure to inspect each component, line and fitting in the refrigerant system for a leak.

Scheme 126

Scheme 127

1. Check for leaks using the special tool. Inspect all components, lines and fittings of the refrigerant system.
2. If a leak is found, recover the refrigerant. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .
3. Repair the refrigerant system leak(s).
4. Evacuate and charge the refrigerant system. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .
5. After the leak(s) is/are repaired, remove any traces of fluorescent dye with a general purpose oil solvent.
6. Verify the repair by running the vehicle for a short period of time and rechecking the area of the leak with the special tool.

Fluorescent Dye Injection - Using an A/C Refrigerant Center and Dye Injector

Note. Before using the R-134a fluorescent dye injector for the first time, refer to the manufacturer's instructions on evacuation of any non-condensable gasses from the hoses.

Note. Only connect the R-134a fluorescent dye injector to a manifold and gauge set or R-134a service center when fluorescent dye is to be injected. The R-134a fluorescent dye injector has a one way check valve that will prevent refrigerant system recovery and evacuation.

Note. Refrigerant system pressure should be between 413-551 kPa (60-80 psi) at 24 °C (75°F) with the engine off.

Scheme 128

Scheme 129

1. Install an R-134a A/C refrigerant service center or a manifold and gauge set. For additional information, refer to «MANIFOLD GAUGE SET CONNECTION»(ref-204566-S31618853942005111300000) .
2. Verify that the valves on the special tool are closed.
3. Fill the special tool reservoir with 7 ml (0.25 oz) of fluorescent dye.
4. Install the special tool between the low-pressure service gauge port valve and the R-134a refrigerant service center or manifold gauge set.
5. Open all valves and inject the fluorescent dye into the refrigerant system.
6. When fluorescent dye injection is complete, close all valves.
7. Recover the refrigerant from the R-134a fluorescent dye injector.
8. Remove the fluorescent dye injector from the low-pressure service gauge port valve and the R-134a A/C refrigerant service center or manifold gauge set.

Fluorescent Dye Injection - Using a Dye Injector Loop Kit

Note. Before using the R-134a fluorescent dye injector for the first time, refer to the equipment manufacturers instructions on evacuation of non-condensable gasses from the hoses.

Note. Refrigerant system pressure should be between 413-551 kPa (60-80 psi) at 24 °C.

Scheme 130

Scheme 131

Scheme 132

Scheme 133

Scheme 134

1. Verify that the valves on the special tool are closed.
2. Fill the special tool reservoir with 7 ml (0.25 oz) of fluorescent dye.
3. Install the special tool between the high-pressure and low-pressure service gauge port valves.
4. Start the engine.
5. Open the high-pressure service valve.
6. Open the special tool valves and inject the fluorescent dye into the refrigerant system.
7. Close the high-pressure service valve to allow the pressure inside the special tool to equalize with the suction side of the refrigerant system.
8. Close the valves on the special tool.
9. Disconnect the high-pressure and low-pressure service valves and remove the special tool from the vehicle.

Scheme 135

Refrigerant System Recovery

Note. Ford Motor Company recommends use of an A/C service center to carry out recovery, evacuation, and charging of the refrigerant system. If an A/C service center is not available, refrigerant system recovery, evacuation, and charging may be accomplished using a separate recovery station, vacuum pump, charging cylinder, and manifold gauge set.

1. Prior to recovering the refrigerant system, you must verify the purity of the refrigerant. For additional information, refer to «REFRIGERANT IDENTIFICATION TESTING»(ref-204566-S20349741062005111300000) .
2. Connect an R-134a A/C service center to the low- and high-pressure service gauge port valves. For additional information, refer to «MANIFOLD GAUGE SET CONNECTION»(ref-204566-S31618853942005111300000) .
3. Recover the refrigerant from the system following the operating instructions provided by the equipment manufacturer.
4. Once the service center has recovered the vehicle A/C system refrigerant, close the service center inlet valve (if equipped). Then switch off the power supply.
5. Allow the vehicle A/C system to remain closed for about two minutes. Observe the system vacuum level as shown on the gauge. If the vacuum does not decrease, disconnect the refrigerant center hose (s).
6. If the system vacuum does decrease, repeat Steps 3 through 5 until the vacuum level remains stable for two minutes.
7. Carry out the required repairs.

Refrigerant System Evacuation

Note. Ford Motor Company recommends use of an A/C service center to carry out recovery, evacuation, and charging of the refrigerant system. If an A/C service center is not available, refrigerant system recovery, evacuation, and charging may be accomplished using a separate recovery station, vacuum pump, charging cylinder, and manifold gauge set.

1. Connect an R-134a service center to the low- and high-pressure service gauge port valves. For additional information, refer to «MANIFOLD GAUGE SET CONNECTION»(ref-204566-S31618853942005111300000) .
2. Evacuate the system until the low-pressure gauge reads at least 99.4 kPa (29.5 in-Hg) of vacuum and as close to 101.1 kPa (30 in-Hg) as possible. Continue to operate the vacuum pump for a minimum of 45 minutes.
3. Turn off the vacuum pump. Observe the low-pressure gauge for five minutes to make sure that the system vacuum is held. If vacuum is not held for five minutes, leak test the system, service the leak, and evacuate the system again.

Refrigerant System Charging

Note. Ford Motor Company recommends use of an A/C service center to carry out recovery, evacuation, and charging of the refrigerant system. If an A/C service center is not available, refrigerant system recovery, evacuation, and charging may be accomplished using a separate recovery station, vacuum pump, charging cylinder, and manifold gauge set.

1. Correctly oil match the system to verify that the correct amount of refrigerant oil is present in the system. For additional information, refer to «REFRIGERANT OIL ADDING»(ref-204566-S33276441792005111300000) .
2. Charge the system with the specified amounts of refrigerant oil and refrigerant.
3. When no more refrigerant is being drawn into the system, start the engine and select FULL COOL operation. Adjust the blower motor speed to the maximum and allow the remaining refrigerant to be drawn into the system. Continue to add refrigerant into the system until the specified weight of R-134a has been added. Close the charging cylinder valve and allow the system to pull any remaining refrigerant from the hose. When the low-pressure drops to approximately 207 kPa (30 psi), close the charging hose valve.

Scheme 136

1. Ford Motor Company has approved a procedure to provide technicians with a non-CFC method of flushing contaminated A/C system heat exchangers, A/C evaporator core, and A/C condenser core. The procedure allows the specific components to be cleaned and flushed while installed in their normal in-vehicle location. The types of contamination flushed include particle matter that results from A/C compressor or desiccant failure within the suction accumulator and gummy residue that can form when refrigerant oil is overheated during A/C compressor seizure. The flushing process is a two-step procedure that involves the use of an A/C Flush and Purge Machine 219-00022 to: Circulate the flushing solvent through the heat exchanger in the reverse direction of normal refrigerant flow (back-flushing). Particulate matter picked up during flushing is filtered from the returning solvent before the solvent is returned to the reservoir for continued circulation. Remove the flushing solvent from the heat exchanger. In this step of the procedure, pressurized air 621-862 kPa (90-125 psi) is used to push and evaporate any remaining flush solvent from the heat exchanger.
2. Discharge the A/C system. Observe all safety precautions. For additional information, refer to the «PROCEDURE»(ref-204566-S37257096232005111300000) .
3. Disconnect the refrigerant lines from the heat exchanger(s) to be flushed.
4. Connect the A/C Flush and Purge Machine 219-00022 and A/C Flush and Purge Fitting Kit 219-00024 to the heat exchanger to be flushed. Do not flush through the evaporator core orifice, mufflers or hoses. Internal plumbing and material make-up of these components make it impossible to correctly remove foreign material or residual flushing solvent.
5. Use 3.785 liters (one gallon) of A/C Systems Flushing Solvent part number F4AZ-19579-A to flush the heat exchanger for a minimum of 15 minutes. The flush solvent may be used for one or both heat exchangers in the A/C system. However, the flush solvent is intended for one vehicle only. The filter used on the flushing unit is also intended for use on one vehicle only.
6. Flush the component for a minimum of 15 minutes.
7. Apply 621-862 kPa (90-125 psi) pressurized air to the component for a minimum of 30 minutes. The 30-minute purge time is required to force and evaporate all residual solvent from the A/C system component. Failure to successfully remove all residual solvent within the component can result in system damage when reconnected and operated. Dispose of the used flush solvent and filter in accordance with local, state and federal emissions.
8. Install a new evaporator core orifice in any vehicle being serviced for A/C compressor or desiccant failure.
9. Install new refrigerant hoses if clogged with foreign material.
10. Reconnect the heat exchanger being serviced.
11. Add additional refrigerant oil as required. For additional information, refer to the «PROCEDURE»(ref-204566-S37257096232005111300000) .
12. Evacuate, leak test and charge the A/C system. For additional information, refer to the «PROCEDURE»(ref-204566-S37257096232005111300000) .
13. Check the system for normal operation.

Scheme 137

Scheme 138

Scheme 139

1. Install the new A/C compressor. For additional information, refer to «AIR CONDITIONING»(ref-204570) .
2. Install the new receiver drier. For additional information, refer to «AIR CONDITIONING»(ref-204570) .
3. Install the new thermostatic expansion valve. For additional information, refer to «AIR CONDITIONING»(ref-204570) .
4. Orient the filter inlet toward the A/C condenser core.
5. Temporarily install the pancake filter between the A/C condenser core and the condenser to evaporator tube (19835). Use flexible refrigerant hose of 17,238 kPa (2,500 psi) burst rating. Make the connections using the R-12/R-134a Air Conditioning Test Fitting Set.
6. Correctly oil match t system. For additional information, refer to «REFRIGERANT OIL ADDING»(ref-204566-S33276441792005111300000) .
7. Evacuate and charge the system. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .
8. Check all refrigerant system hoses, lines and the position of the newly installed filters to be sure they do not interfere with other engine compartment components. If necessary, use tie straps to make adjustments.
9. Provide adequate airflow to the front of the vehicle (with a fan, if necessary). Select A/C operation and set the blower motor speed to maximum. Start the engine and let it idle briefly. Make sure the A/C system is operating correctly.
10. Gradually bring the engine up to 1,200 rpm by running it at lower rpms for short periods (first at 800 rpm, then at 1,000 rpm). Set the engine at 1,200 rpm and run it for one hour with the A/C system operating.
11. Stop the engine.
12. Recover the refrigerant from the system. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .
13. Remove the fittings, flexible hoses and pancake filter from between the A/C condenser core and the condenser to evaporator tube.
14. Discard the pancake filter. It can be used one time only.
15. Reconnect the condenser to evaporator tube to the A/C condenser core.
16. Evacuate and charge the system. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .

Refrigerant Oil Adding

Note. Installation of new components such as the A/C pressure transducer do not require additional oil.

1. Rotate the A/C compressor shaft six to eight revolutions while collecting the oil in a clean measuring device. If the amount of oil drained from the old A/C compressor is between 90-150 ml (3-5 ounces), pour the same amount plus 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSHM1C231-B into the new A/C compressor. If the amount of oil that was removed from the old A/C compressor is greater than 150 ml (5 ounces), pour the same amount drained of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSHM1C231-B into the new A/C compressor. If the amount of oil that was removed from the old A/C compressor is less than 90 ml (3 ounces), pour 90 ml (3 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B into the new A/C compressor.
2. For the receiver drier, drill one 12.7 mm (0.5 in) hole in the receiver drier cylinder and drain the oil into a calibrated container. Add a quantity of new oil to match that drained from the old receiver drier plus 59 ml (2 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B.
3. For the A/C evaporator core add 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSHM1C231-B to the receiver drier inlet tube.
4. For the A/C condenser core, add 30 ml (1 ounce) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSHM1C231-B to the A/C condenser core or the receiver drier inlet tube.
5. Add 20 ml (.75 ounces) of clean PAG Refrigerant Compressor Oil (R-134a Systems) F7AZ-19589-DA (Motorcraft YN-12-C) or equivalent meeting Ford specification WSH-M1C231-B to the receiver drier inlet tube when carrying out each of the following repairs: installation of a new TXV installation of a new A/C compressor pressure relief valve (19D644) installation of a new refrigerant line repair of an O-ring seal leak repair of a charge port leak

1. Follow the instructions included with the Deluxe Refrigerant Diagnostic Tool to obtain the sample for testing.
2. The diagnostic tool will display one of the following: If the purity level of R-134a or R-12 is 98% or greater by weight, the green "PASS" light emitting diode (LED) will light. The weight concentrations of R-134a, R-12, R-22, hydrocarbons, and air will be displayed on the digital display. If refrigerants R-134a or R-12 do not meet the 98% purity levels, the red "FAIL" LED will light and a horn will sound alerting the user of potential hazards. The weight concentrations of R-134a, R-12, R-22, and hydrocarbons will be displayed on the digital display. If hydrocarbon concentrations are 2% or greater by weight, the red "FAIL" LED will light, "Hydrocarbon High" will be displayed on the digital display, and a horn will sound alerting the user of potential hazards. The weight concentrations of R-134a, R-12, R-22, and hydrocarbons will also be displayed on the digital display.
3. The percentage of air contained in the sample will be displayed if the R-134a or R-12 content is 98% or greater. The diagnostic tool eliminates the effect of air when determining the refrigerant sample content because air is not considered a contaminant, although air can affect A/C system performance. When the diagnostic tool has determined that a refrigerant source is pure (R-134a or R-12 is 98% or greater by weight) and air concentration levels are 2% or greater by weight, the diagnostic tool will prompt the user if an air purge is desired.
4. If contaminated refrigerant is detected, repeat the refrigerant identification test to verify that the refrigerant is indeed contaminated.
5. Recover any contaminated refrigerant using suitable recovery-only equipment designed for capturing and storing contaminated refrigerant. For additional information, refer to «CONTAMINATED REFRIGERANT HANDLING»(ref-204566-S05135856122005111300000) .

Contaminated Refrigerant Handling

1. Recover the contaminated refrigerant using suitable recovery-only equipment designed for capturing and storing contaminated refrigerant. This equipment must only be used to recover contaminated refrigerant to prevent the spread to other vehicles. If this equipment is not available, contact an A/C repair facility in your area with the correct equipment to carry out this repair.
2. Determine and correct the cause of the customer's initial concern.
3. Remove the receiver drier. For additional information, refer to «AIR CONDITIONING»(ref-204570) .
4. Clean the A/C evaporator core and the A/C condenser core by flushing. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM FLUSHING»(ref-204566-S13289368662005111300000) .
5. Install the new receiver drier. For additional information, refer to «AIR CONDITIONING»(ref-204570) .
6. Correctly oil match the system. For additional information, refer to «REFRIGERANT OIL ADDING»(ref-204566-S33276441792005111300000) .
7. Evacuate and charge the system. For additional information, refer to «AIR CONDITIONING (A/C) SYSTEM RECOVERY, EVACUATION AND CHARGING»(ref-204566-S12281990922005111300000) .
8. Dispose of contaminated refrigerant according to all federal, state and local regulations.