Check of serviceability of functioning and maintenance of heating systems and air-conditioning

1. The following safety checks should be carried out on a regular basis in order to maintain the air conditioning system in good working order: a) Check the condition of the compressor drive belt. In case of defects or signs of wear, replace (see. Chapter Settings and maintenance); b) Check the tension of the drive belt, if necessary, make the appropriate adjustment (see chap. Adjustment and routine maintenance); c) Check the hoses of a refrigerator path for cracks, blisters, signs of curing and aging of rubber, evaluate the state of compression fittings. Replace defective components; d) Check the condenser plate heat exchanger for jammed between the remains of insects, old leaves and other debris. If necessary, clean the gaps fine brush or blow with compressed air; e) Check the charge level of the system; f) In the presence of liquid drips in the vicinity of the instrument panel or on mats check patency of the drainage tube evaporator.

2. The air conditioning system should include at least 10 minutes at least once a month (even in winter). Prolonged inactivity K / V leads to hardening and damage the O-rings and sleeves connecting tract.
3. In view of the complexity of the design of the system and the need to use special equipment, its maintenance, deep diagnostics and regenerative repair lie outside the qualification of the average mechanic-fan and must be performed in the workshop car service. The competence of the owner of the car gets only listed later in this section just checking and replacing.
4. The most common cause of infringement of serviceability of functioning of C / B is a reduction of the charge of refrigerator oil.
5. The following simple test will quickly reveal signs of reducing the refrigerant.

1. Warm up the engine to normal operating temperature.
2. Turn on the A / C service for maximum cooling capacity. Select the maximum fan speed mode. Open the doors to avoid cyclic system shutdowns when cooling in a closed cabin volume.
3. When the system temperature reaches operating temperature, felt the two connected to the evaporator on the bulkhead engine compartment of the tube.

4. More than a thin tube that goes to the evaporator from the condenser outlet nozzle must be sufficiently cold to the touch. Thicker tube running from the exhaust nozzle of the evaporator back to the compressor must be a little (2 - 6 degrees) colder. If the discharge pipe touch noticeably warmer intake, so the system needs to be recharged. Enter a thermometer in the outlet duct through the central vent on the dashboard. When the K / temperature exiting the vent air should be about 19 - 22 degrees below the ambient temperature (up to a value of 4.5 ?� C). In very hot weather conditions (40 ?� C), it is acceptable to increase the level of outlet temperature 15.7 ?� C, but no more. If the air conditioner does not provide the required intensity of cooling should make a charging system. For a more detailed diagnosis of the condition of the car should be driven away in a specialized workshop.

5. If the intensity of the cooling air supplied to the interior is not sufficient, the system probably needs to be recharged.
6. If there is evidence of a complete system failure Check the operation of the compressor clutch.
7. Looking at the front side of the compressor, ask the assistant to include K / V. clutch shall publish a distinct click, and its central part - begin to spin, otherwise switch off the engine and remove the gauge-switch of the system. Close the jumper wire between a connector terminal and re-operate the air conditioner. Now, if the system will start to function properly, so the pressure in the extreme high or low - drive to a service station.
8. If the clutch still does not work, check the appropriate fuse is located inside the vehicle assembly block.
9. Remove the engine compartment located in the mounting block compressor clutch relay and check that its operation (see chap. Onboard electric equipment). When removed, the relay and the ignition on, check if the power supply to the two terminals of the relay in the mounting block (see. The wiring diagram at the end of the Head the Onboard electric equipment).
10. With the jumper wire, connect the power terminals of the compressor clutch relay in the mounting block (see. Wiring diagram) to the terminal coupling - coupling must publish a click. If it does not click, disconnect the wiring from the grip and check that the power supply to its connector. Check the grounding terminal black wire connectors. If the wiring is OK, replace the clutch assembly of the compressor.
11. If all the components and wiring in order, and the system is charged to the required level, the car should be driven away on a car repair shop to perform diagnostics and regenerative repair of PCM.
12. A more detailed diagnosis of the air conditioning is outside the qualification of the average mechanic-fan and its implementation should be entrusted to experts of car-care center.

1. Prepare a set of standard charge R-134 (ask in shops of automobile accessories). The kit includes a can of refrigerant oil of 12 oz (ounce), a gate nozzle and the length of the hose connected between valve and fitting of the low pressure refrigerant path. As a spray oil may not be enough to finalize the charging system, it makes sense in any case to buy a pair immediately. Make sure that at least one of the cans of oil was tinted in red, which will quickly detect refrigerant leaks in the event of such. In no case do not refuel in more than two cans of refrigerant!

2. In accordance with the manufacturer's instructions, connect the charge set to the low pressure of the refrigerant path.
3. Close the valve on the adapter nozzle and screw on the latest spray head, ensure beforehand in the presence of O-ring / rubber gasket.

Be sure to wear safety glasses!

4. Remove the dust cap from the union of the low-pressure refrigerant path, and reconnect the fitted connector hose quick docking charger set. Construction choke nodes will not allow to make a connection to a set of high-pressure part of the tract.

5. Warm up the engine to normal operating temperature and turn on the A / C service. Make sure to set the charging hose does not touch the fan blades of the engine cooling system / air conditioning and other moving components in the engine compartment. Charging systems must be carried out when the compressor is running. If the compressor clutch is disabled, the system should be switched to the maximum cooling capacity, and open all the doors of the cabin. To the compressor from turning off during charging, disconnect the connector from the gauge-switch of low pressure (on some models use the combined sensor switch low / high pressure) and Jumper his paper clip or stiff wire segment.

6. Turn the nozzle gate head pierce the balloon, opening the flow of refrigerant (must be heard the distinctive sound of escaping gas). During the entire charging keep spray vertically, from time to time shaking it. In the series charging pause necessary to stabilize the system.

In no case do not pumped into the system more than two cans of refrigerant! To avoid icing spray during refueling wrap it dipped in warm water with a towel.

7. If you have at hand accurate thermometer, enter it in through the vent in the central duct K / B and make sure the temperature of air submitted to salon.
8. When the cartridge is empty, close the valve and disconnect the hose from the low-pressure nozzle system. Immediately put on fitting the dust cap.
9. Disconnect from the spray nozzle gate, if necessary, reposition it on the second canister and continue filling. Upon completion of the procedure put unfinished spray upright on the rack, and when necessary use it to recharge the system.

1. Moisturize carpet on the floor under the heater heat exchanger or steam outlet duct through the baffles say about leaks of the heat exchanger. Remove the heat exchanger (see. Section Removal and installation of the heat exchanger heater) and replace it with a new one (regenerative heat exchanger heater can not be repaired).
2. If the heater does not provide proper heating of air submitted to salon, the reason for this failure could be one of the following:

a) The thermostat is stuck in open position that is not supplied to the heat exchanger allows heating the engine coolant to warm up to normal temperature. Replace the thermostat (see. Section Check of serviceability of functioning and thermostat replacement);
b) there is a violation of patency of the cooling tract, which blocks the flow of coolant into the heat exchanger of a heater. Felt hoses connected to the branch pipes on the rear bulkhead engine compartment - both must be hot, otherwise broken cross tract (blocked pipes, heat exchanger or heater control valve). Disconnect hoses and make obratnopotochnuyu flushing the heat exchanger. Pre disconnected, wash as both hoses;
c) If the restore patency of the heat exchanger by washing is not possible, it should be made to replace it (see. Section Removal and installation of the heat exchanger heater ).

1. Unpleasant odors often arise when the K / V causes the formation of mold colonies on the plates of the evaporator coil. Warm moist environment creates favorable conditions for the emergence and development of fungal microorganisms.
2. Access to the evaporator heat exchanger on most models is extremely limited. The procedure of guaranteed complete mold removal performed in the workshop car service is quite labor-intensive, time-consuming and requires the use of strong disinfectants. In principle, it is enough effective treatment can be performed at home and own vehicle owner.
3. Special disinfectants in aerosol packaging, designed to serve air conditioning systems, can be purchased at almost any shop of automobile accessories. It should be remembered that the price of money is usually directly proportional to its effectiveness. Switch the system into a closed air circulation and ten minutes turn the heater fan to maximum speed. For the purpose of drying systems include heating at a maximum intensity. Disconnect the electrical wiring from the compressor in order to prevent its operation.

4. Submission of funds is usually done through a long hose. Remove Resistor electric heater fan drive (see. Section Removal and installation of an electric motor driving the fan heater), enter the nozzle flow nozzle in the hole and move it to the left, right at the evaporator. Supply means in accordance with the manufacturer's instructions. Try to maximize the whole surface of the heat exchanger. The duration of each treatment cycle, and the intervals between the series must be indicated on the label of the container.

5. The best preventive measure against the occurrence of colonies of mold in the heat exchanger of the evaporator is regular checking patency of the drainage tube, as well as short-term switch-mode condensate after each long-distance trips with working air conditioning for the purpose of drying the evaporator.

The additional complete set of cars Nissan Maxima may include a climate control system. Operation of the system runs its own processor that receives the necessary input from the various information sensors. As the PCM processor includes a self-diagnosis, enables rapid troubleshooting. The operator selects the desired temperature and puts it through a special handle on the control panel. Next, the system begins to automatically maintain the desired temperature of the air inside the vehicle by adjusting accordingly the supply of cold and / or hot air. High-speed mode of operation of the fan is also controlled by the microprocessor through the series-connected controller, replacing in this case the resistor assembly. Full fault diagnostics and repair of the climate control system is outside the qualification of the average mechanic-fan. However, the processor is equipped with an on-board self-diagnostics with the ability to highlight DTC.