Air Conditioning System: Other Suzuki Forenza I

Compressor

All compressors are belt-driven from the engine crankshaft through the compressor clutch pulley. The compressor pulley rotates without driving the compressor shaft until an electromagnetic clutch coil is energized. When voltage is applied to energize the clutch coil, the clutch plate and hub assembly is drawn rearward toward the pulley. The magnetic force locks the clutch plate and pulley together as one unit to drive the compressor shaft.

As the compressor shaft is driven, it compresses the low-pressure refrigerant vapor from the evaporator into a high-pressure, high-temperature vapor. The refrigerant oil which is used to lubricate the compressor is carried with the refrigerant. Refer to V5 A/C System Description .

Condenser Core

The condenser assembly in front of the radiator consists of coils which carry the refrigerant, and cooling fins that provide the rapid transfer of heat. The air passing through the condenser cools the high-pressure refrigerant vapor and causes it to condense into a liquid.

Expansion Valve

The expansion valve is located with the evaporator core, on the front passenger side fire wall.

The expansion valve can fail in three different positions: open, closed or restricted.

An expansion valve that fails in the open position will result in a noisy A/C compressor or no cooling. The cause can be a broken spring, a broken ball, or excessive moisture in the A/C system. If the spring or the ball are found to be defective, replace the expansion valve. If excessive moisture is found in the A/C system, recycle the refrigerant.

An expansion valve that fails in the closed position will result in low suction pressure and no cooling. This may be caused by a failed power dome or excessive moisture in the A/C system. If the power dome on the expansion valve is found to be defective, replace the expansion valve. If excessive moisture is found in the A/C system, recycle the refrigerant.

A restricted expansion valve will result in low suction pressure and no cooling. This may be caused by debris in the refrigerant system. If debris is believed to be the cause, recycle the refrigerant, replace the expansion valve, and replace the receiver-dryer.

Evaporator Core

The evaporator is a device which cools and dehumidifies the air before it enters the vehicle. High-pressure liquid refrigerant flows through the expansion tube orifice and becomes a low-pressure gas in the evaporator. The heat in the air passing through the evaporator core is transferred to the cooler surface of the core, which cools the air. As the process of heat transfer from the air to the evaporator core surface is taking place, any moisture or humidity in the air condenses on the outside surface of the evaporator core and is drained off as water.

Receiver-Dryer

The sealed receiver-dryer assembly is connected to the condenser outlet pipe. It acts as a refrigerant storing container, receiving liquid, vapor and refrigerant oil from the evaporator.

At the bottom of the receiver-dryer is the desiccant, which acts as a drying agent for the moisture that may have entered the system. An oil bleed hole is located near the bottom of the receiver-dryer outlet pipe to provide an oil return path to the compressor. The receiver-dryer is serviceable only as an assembly.

Heater Core

The heater core heats the air before it enters the vehicle. Engine coolant is circulated through the core to heat the outside air passing over the fins of the core. The core is functional at all times and may be used to temper conditioned air in the A/C mode as well as in the heat or the vent modes.

Controller

The operation of the A/C system is controlled by the switches and the lever on the control head. The compressor clutch and the blower are connected electrically to the control head by a wiring harness. The blower circuit is open in the OFF mode. Airflow is provided by the four blower speeds available in the remaining modes. Cooled and dehumidified air is available in the MAX, NORMAL, BI-LEVEL and DEFROST modes.

The temperature is controlled by the position of the temperature knob on the control head. A cable connects this knob to the temperature door, which controls the airflow through the heater core. As the temperature knob is moved through its range of travel, a sliding clip on the cable at the temperature valve connection should assume a position ensuring that the temperature door will seat in both extreme positions. The temperature door position is independent of the mode control switch.

The electric engine cooling fan on some vehicles is not part of the A/C control system; however, the fan is operational any time the A/C control is in the MAX, NORMAL or BI-LEVEL modes. Some models provide for engine cooling fan operation when the controller is in the DEFROST mode. This added feature is part of the A/C controller function and is aimed at preventing excessive compressor head temperatures. It also allows the A/C system to function more efficiently. On some models, the engine cooling fan will be turned off during road speed conditions above 56 km/h (35 mph), when the airflow though the condenser coil is adequate for efficient cooling. The operation of the cooling fan is controlled by the Powertrain Control Module (PCM), or the Engine Control Module (ECM), through the cooling fan relay.

Pressure Transducer

The pressure transducer incorporates the functions of the high-pressure and the low-pressure cutout switches along with the fan cycling switch. The pressure transducer is located in the high-side liquid refrigerant line near the right front strut tower and the air filter assembly.

Wide-Open Throttle (WOT) Compressor Cutoff

During full throttle acceleration on vehicles equipped with Multi-Port Injection (MPI), the Throttle Position Sensor (TPS) sends a signal to the PCM or the ECM, which then controls the compressor clutch.

A/C Time Delay Relay

This relay on some vehicles controls the current to the entire A/C system and provides a short delay of A/C operation upon start-up.

Insufficient Cooling "Quick Check" Procedure

Perform the following "hand-feel" procedure to get a quick idea of whether the A/C system has the proper charge of Refrigerant-134a. The air temperature must be above 21 °C (70 °F) for most models.

1. Warm up engine. Run the engine at idle.
2. Open the hood and all the doors.
3. Turn the A/C switch ON.
4. Set the temperature control to the full cold position.
5. Set the blower speed switch on the maximum speed setting.
6. "Hand-feel" the temperature of the evaporator outlet pipe. The pipe should be cold.
7. Check for other problems. Refer to «Testing the Refrigerant System»(ref-257102-S03778825632007062900000) .
8. Leak check the system. Refer to «Leak Testing Refrigerant System»(ref-257102-S14835443392007062900000) . If you find a leak, discharge the system and repair the leak as required. After completing the repair, evacuate the system and charge it.
9. If there is no leak, refer to «Insufficient Cooling Diagnosis»(ref-257102-S16364877322007062900000) .

Liquid Leak Detectors

Use a liquid leak detector solution on locations such as fittings. Apply the solution to the area in question with the swab that is supplied with the solution. Look for bubbles to appear. This will indicate the existence and the location of any leak.

For areas where this is not practical, such as sections of the evaporator and the condenser, an electronic leak detector is more useful.

Electronic Leak Detectors

Follow the manufacturer's instructions for calibration, operation, and maintenance of an electronic leak detector. Battery condition is especially important to the accuracy of a portable model. Set the detector to R- 134a before beginning the test.

Handling Refrigerant

Air conditioning systems contain refrigerant. This is a chemical mixture which requires special handling procedures to avoid personal injury.

Always wear goggles and wrap a clean cloth around the fittings, the valves and the connections when performing work that involves opening the refrigerant system. Do not weld or steam clean on or near any vehicle-installed air conditioning lines or components.

All refrigerant drums are shipped with a heavy metal screw cap. The purpose of the cap is to protect the valve and the safety plug from damage. It is good practice to replace the cap after each use of the drum.

If it is necessary to transport or carry any container of refrigerant in a vehicle, do not carry it in the passenger compartment.

Handling of Refrigerant Lines and Fittings

1. Keep all metal tubing lines free of dents or kinks. Any line restrictions will cause the loss of system capacity.
2. Never bend a flexible hose line to a radius of less than four times the diameter of the hose.
3. Never allow a flexible hose line to come within 65 mm (2-1/2 in.) of the exhaust manifold.
4. Inspect flexible hose lines regularly for leaks or brittleness.
5. Replace flexible hose lines with new lines if you find signs of deterioration or leaking.
6. Discharge all refrigerant of the refrigeration system before disconnecting any fitting in the refrigeration system.
7. Proceed very cautiously regardless of the gauge readings. WARNING: Keep your face and your hands away from the fitting so that you will not be injured if there happens to be liquid refrigerant in the line.
8. Open the fittings very slowly.
9. If you notice pressure when you loosen a fitting, allow the pressure to bleed off as described under «Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System»(ref-257102-S08954628872007062900000) .
10. Cap or tape any refrigerant line immediately after it is opened. This will prevent the entrance of moisture and dirt, which can cause internal compressor wear or plugged lines in the condenser, the evaporator core, the expansion valve, or the compressor inlet screens. NOTE: Use two proper wrenches to connect the O-ring fittings.
11. Back up the opposing fitting to prevent distortion of the connecting lines or the components.
12. Back up both the swagged fitting on the flexible hose connections and the coupling to which it is attached with two wrenches to prevent turning the fitting and damaging the ground seat.
13. Keep the O-rings and the seats in perfect condition. A burr or a piece of dirt may cause a refrigerant leak.
14. Dip new O-rings in clean polyalkaline glycol refrigerant oil before installation.

Maintaining Chemical Stability in Refrigeration System

The efficient operation and the life of the air conditioning (A/C) system is dependent upon the chemical stability of the refrigeration system. When foreign materials, such as dirt, air, or moisture, contaminate the refrigeration system, they will change the stability of the refrigerant and the Polyalkaline Glycol (PAG) compressor oil. They will also affect the pressure-temperature relationship, reduce efficient operation, and can possibly cause interior corrosion and abnormal wear of moving parts.

Observe the following practices to ensure chemical stability in the system

1. Wipe away dirt or oil at and near any connection before opening that connection. This will reduce the chance of dirt entering the system.
2. Cap, plug, or tape both sides of a connection as soon as possible after opening the connection. This will prevent the entry of dirt, foreign material, and moisture.
3. Keep all tools clean and dry, including the manifold gauge set and all replacement parts.
4. Use a clean and dry transfer device and container to add polyalkaline glycol refrigerant oil. This will ensure that the oil remains as moisture-free as possible. Refer to «Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System»(ref-257102-S08954628872007062900000) .
5. Have everything you need ready to allow you to perform all operations quickly when opening an A/C system. Do not leave the A/C system open any longer than necessary.
6. Evacuate and recharge any A/C system that has been opened. Refer to «Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System»(ref-257102-S08954628872007062900000) for the instructions to perform this procedure properly.

All service parts are dehydrated and sealed before shipping. They should remain sealed until just before making connections. All the parts should be at room temperature before uncapping. This prevents condensation of moisture from the air from entering the system. Reseal all parts as soon as possible.

Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System

A charging station discharges, evacuates, and recharges an air-conditioning (A/C) system with one hookup. Filtering the refrigerant during the recovery cycle together with filtering during the evacuation cycle ensures a supply of clean, dry refrigerant for A/C system charging.

Control Panel Functions

A charging station will have controls and indicators to allow the operator to control and monitor the operation in progress. These can be expected to include the following

1. Main Power Switch Supplies electrical power to the control panel.
2. Display Shows the time programmed for vacuum. Shows the weight of the refrigerant programmed for recharging.
3. Low-Side Manifold Gauge Shows the system's low-side pressure.
4. High-Side Manifold Gauge Shows the system's high-side pressure.
5. Controls Panel Controls the various operating functions.
6. Low-Side Valve Connects the low side of the A/C system to the unit.
7. Moisture Indicator Shows whether the refrigerant is wet or dry.
8. High-Side Valve Connects the high side of the A/C system to the unit.

Refrigerant Recovery

1. Attach the high-side hose with the quick disconnect coupler to the high-side fitting of the vehicle's A/C system.
2. Open the coupler valve.
3. Attach the low-side hose with the quick disconnect coupler to the low-side fitting of the vehicle's A/C system.
4. Open the coupler valve.
5. Check the high-side and the low-side gauges on the unit's control panel in order to ensure that the A/C system has pressure. If there is no pressure, there is no refrigerant in the system to recover.
6. Open both the high-side and the low-side valves.
7. Open the gas and the liquid valves on the tank.
8. Drain any oil that may be in the oil separator.
9. Close the oil drain valve.
10. Plug the unit into the proper voltage outlet.
11. Turn on the main power switch.
12. Begin the recovery process.
13. Wait 5 minutes, then check the control panel low-side gauge. If the A/C has maintained vacuum, the recovery is complete.
14. If the low-side gauge pressure rises above zero, there is more refrigerant in the system. Recover the additional refrigerant. Repeat this step until the system maintains vacuum for 2 minutes.

Evacuation

The unit tank must contain a sufficient amount of R-134a refrigerant for charging. Check the amount of refrigerant in the tank. If there is less than 3.6 kg (8 pounds) of refrigerant, add new refrigerant to the tank.

1. Verify that the high-side and the low-side hoses are connected to the A/C system. Open both the high-side and the low-side valves on the unit's control panel.
2. Open both the gas and the liquid valves on the tank.
3. Start the vacuum pump and begin the evacuation process. Non-condensable gases (mostly air) are vented from the tank automatically during the recycling process. You may hear the pressure being released.
4. Check for leaks in the system.

A/C System Oil Charge Replenishing

Any oil removed from the A/C system during the recovery process must be replenished at this time.

1. Use the correct graduated bottle of PAG oil for the R-134a system.
2. Add the proper amount of PAG oil to the system.
3. Close the valve when the required oil charge has been pulled into the system.

Charging

Note. Evacuate the A/C system before charging.

1. Close the low-side valve on the control panel.
2. Open the high-side valve on the control panel.
3. Enter the amount of refrigerant needed to charge the A/C, making sure to use the correct system of measurement, i.e. kilogram (kg) or pound (lb).
4. Begin the charging process.

Successful Transfer Complete

1. Close the high-side valve on the unit's control panel. Both valves should be closed.
2. Start the vehicle and the A/C system.
3. Let the engine run until the readings on the high-side gauge and the low-side gauge stabilize.
4. Compare the readings to the system specifications.
5. Check the evaporator outlet temperature to ensure that the A/C system is operating within the system specifications.
6. Keep the A/C running.
7. Close the high-side coupler valve.
8. Disconnect the high-side hose from the vehicle.
9. Open the high-side and low-side valves on the control panel. The system will quickly draw in refrigerant from both hoses through the low-side hose.
10. Close the low-side coupler valve.
11. Disconnect the low-side hose from the vehicle.

Unsuccessful Transfer

Sometimes the total charge does not transfer into the A/C system. There are two reasons why this may occur

1. The pressure in the unit's tank and the pressure in the A/C system are roughly equal. This will cause the transfer to proceed too slowly.
2. There was not enough refrigerant in the unit's tank to transfer the full charge. It is necessary to recover the partial charge of refrigerant from the vehicle and then evacuate the A/C system and charge it again. Refer to the manufacturer's instructions for the charging station in use.

Components Used in Non-A/C Systems

Refer to heating and ventilation system section for on-vehicle service procedures for the following sections

1. Blower Motor
2. Blower Resistor
3. Control Assembly Knob Lighting
4. Control Assembly
5. Heater Hoses
6. Temperature Control Cable
7. Heater/Air Distributor Case Assembly (A/C Module)
8. Heater Core

Scheme 98

1. Disconnect the negative battery cable.
2. Recover the refrigerant. Refer to «Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System»(ref-257102-S08954628872007062900000) .
3. Release the connector lock and pull the transducer wire connector out.
4. Remove the transducer with a wrench.
5. Discard the O-ring seal.

Scheme 99

1. Install the new O-ring seal on the transducer.
2. Install the pressure transducer. Tighten: Tighten the pressure transducer to 7 N.m (62 lb-in).
3. Connect the wire connector.
4. Connect the negative battery cable.
5. Recover the refrigerant. Refer to «Discharging, Adding Oil, Evacuating, and Charging Procedures for A/C System»(ref-257102-S08954628872007062900000) .

Scheme 100

1. Disconnect the negative battery cable.
2. Pull the relay straight up and out from its location in the engine fuse block at the left front corner.