| Topic | Summary |
| Air-conditioning ECU |
The electronic control is connected to the sensors and actuators by a multi-plug, and through wiring to the main vehicle wiring harness. |
| Ambient air temperature sensor |
The cabin air temperature is continually measured by the cabin air temperature sensor. When the cabin air temperature has been changed to be within 2°C or 35°F of the desired selection, the fan speed is gradually reduced. |
| Servo motors |
Vacuum servos consist of a sealed housing divided by a flexible diaphragm. The diaphragm seals the housing into two separate chambers. |
| Electric servo motors |
Electrical servos incorporate limit switches to open circuit the current supply to the motor when the maximum travel of the flap or tap has been reached. |
| Automatic climate control sensors |
Most temperature sensors used in climate control systems are thermistors which are solid state electronic devices that change their electrical resistance in response to temperature changes. |
| Evaporator temperature sensor |
The evaporator temperature sensor is located in the air stream where the air leaves the evaporator and signals to the control unit the temperature of the air. |
| Blower speed control |
This controls the speed of the fan in the heating and air-conditioning system in the passenger cabin. |
| Ventilation systems | A ventilation system is fitted to vehicles to make the environment in the cabin comfortable for its occupants. The ventilation system is controlled by a set of switches located on the dash. |