LEXUS RX 300

1998 — 2003 of release

Repair and operation of the car

Systems of heating, ventilation and air conditioning

General information

Description of systems

The system of heating consists of the fan and the heat exchanger located in the uniform block. Hot OZh passes through the heat exchanger. When moving the handle of management of the modes of a heater located on the dashboard the gate opens, and hot air begins to come to interior of the car. If to turn on the heater fan, air will move in salon more intensively. The fan can work with different degree of intensity. For a possibility of rotation of the fan with various speed the resistor is installed. At the closed OZh gate comes on a small contour back to an engine radiator contour.

Components of system of heating and To/in in salon

1 — the Sensor of the sun 2 — temperature Sensor in salon 3 — the Control unit 4 — the Broad valve 5 — the Evaporator 6 — Э / the motor of supply of external air	7 — the Filter of system of ventilation 8 — Э / the fan motor 9 — the Relay э / the fan motor 10 — Э / the motor of production of air 11 — Э / the air mixing motor 12 — the heater Heat exchanger 13 — the evaporator temperature Sensor

Before getting to salon, air passes through the filter in which the main share of dust settles. It is necessary to observe frequency of replacement of the filter since the filter hammered with dust limits air supply that will lead to an air stagnation in salon.

Distribution of streams of air of system of ventilation is carried out also by means of gates. On all models the air circulation mode is provided.

The air conditioning system (K/V) is included in a basic equipment of the cars considered in the present manual.

Works with the K/V system have to be performed in a specialized workshop. Do not open a coolant circulation contour as at contact with skin coolant can cause a frostbite. Procedures of repair of the K/V system in the present manual are not considered.

By means of the K/V system can lower air temperature in salon rather external temperature. During the work of system humidity in salon decreases. During wet weather, the arriving fresh air previously it is cooled then again heats up to the set temperature. Thus its drainage is made. By means of this procedure it is possible to get rid of fogging of glasses.

The K/V system consists of the compressor, the condenser, the evaporator, container with coolant and pipelines. In system coolant (R134a type) which depending on temperature and pressure can be in liquid or gaseous state circulates.

Components of the K/V system in a motive compartment

1 — the Condenser 2 — Assembly of fans (the condenser fan) 3 — the Compressor and the magnetic coupling 4 — the Relay of the magnetic coupling	5 — the Block of the relay and safety locks in a motive compartment 6 — pressure Sensor 7 — the Sensor of temperature of external air

The compressor of the conditioner is given by a multiridge belt from a bent shaft of the engine. He creates pressure in a contour of the coolant representing gas and causes its heating. In the condenser coolant is cooled with external air. Thereof the warmed coolant is condensed, turning into liquid. Under high pressure it is passed via the valve therefore its pressure falls. After that coolant evaporates in a contour, at the same time strongly being cooled. In the evaporator coolant selects heat from the air blown through it. Thereof air is cooled. The cooled air comes to interior of the car. As a result of heating in the evaporator coolant turns into gas and under low pressure comes to the compressor then process of circulation repeats.

Security measures at service To/in

The K/V system has to be served by exclusively prepared technicians trained in safe working methods with use of the appropriate equipment and with observance of rules of depressurization, and also acquainted with methods of collecting and storage of automobile coolant.

• Do not allow contact of coolant with skin;
• During the work near air conditioning system put on goggles;
• At hit of coolant on skin or in eyes do not pound the struck place. Immediately wash out an affected area cold water within not less than 15 minutes. Immediately ask for medical care in medical institution. Self-treatment is not allowed;
• Coolant is stored in a new cylinder under pressure. You store a cylinder at a temperature not above the +50th hail. Take the measures excluding falling of a cylinder about heights or other situations which can lead to its damage;
• Works should be carried out in well aired room. Coolant quickly evaporates, leads to reduction of access of oxygen and the complicated breath;
• Gaseous coolant is heavier than air and rather quickly has to gather below, for example, under the car;
• At combustion of coolant poisonous gas is formed. You store coolant far from open sources of fire. You do not smoke at work with the K/V system;
• When carrying out welding works near the K/V system do not subject to its influence high temperature or an open flame. The overheat can lead to increase in pressure in system and to ignition;
• Cleaning of the condenser or evaporator by means of water vapor is not allowed. It is necessary to use only cold water or compressed air.