During the cooling cycle, some fluid flows into the interior heater heat exchanger as well as into the throttle body to maintain its operating temperature.
The spring thermostat is located in the housing on the engine. When the engine warms up, a closed thermostat cuts off the flow of fluid into the radiator. When the engine reaches operating temperature, the thermostat opens and fluid flows into the radiator, where it cools before a new cycle.
The system is hermetically sealed with a spring-loaded lid, which has a safety valve, as well as a vacuum valve through which the system can communicate with the atmosphere. By maintaining a certain pressure in the system, the boiling point of the coolant is reduced. When the pressure reaches a critical value, the lid valve lifts from the seat, resulting in the release of steam from the system.
When the engine is not warmed up, fluid from the expansion tank flows into the radiator. As the temperature rises, hot liquid steam enters the tank from the radiator.
The design of the described vehicles provides for the presence of an electric viscous coupling. The clutch/fan is controlled from the PCM. Working cycles are carried out in accordance with the signals from the information sensors of the control system.
The interior is heated by passing outside air through the heater, which is a small heat exchanger located behind the vehicle's dashboard. The heater is heated by hot liquid from the engine cooling system, and outside air enters the passenger compartment through air ducts. The heating temperature is adjusted by mixing the hot air that has passed through the heater with outside air at ambient temperature. Mixing occurs when the air duct dampers are controlled, as well as when the heater fan speed changes.
The rear part of the cabin is heated due to the presence of an additional heat exchanger located at the rear of the car.
The vehicles described here are equipped with a basic air conditioning system consisting of an evaporator located under the dashboard, a condenser located in front of the radiator, a filter drier in the engine compartment and a belt-driven compressor located in front of the engine. Air conditioning in the rear compartment is provided by an additional evaporator located at the rear of the vehicle.