The temperature in the passenger compartment can be set by two switches on the left and right sides of the car. In accordance with the position of the switches and the current temperature, the electronic unit in the heater control panel regulates the opening time of the valves. The interior temperature sensors are located behind the heater. Thanks to the presence of electronic control, a constant temperature in the cabin is maintained, regardless of the speed of movement and the outside temperature.
To increase the performance of the heater, a heater fan with four control stages is designed. To ensure different fan speeds, ballast resistors are switched on at different stages. If one of the resistors fails, the fan does not run at the appropriate speed.
Attention: Models equipped with air conditioning are not considered below. In addition to maintenance (A/C compressor V-belt tension) all work related to the air conditioner must be carried out at a service station.