Working principle of air conditioning heating:
According to the types of heat sources, automobile heating systems are mainly divided into two types: one is to use engine coolant as the heat source (currently used by most vehicles), and the other is to use fuel as the heat source (used by a few middle and high-class vehicles).
When the engine coolant temperature is high, the coolant flows through the heat exchanger in the heating system (generally referred to as the small heater tank), and the air sent by the blower exchanges heat with the engine coolant. After being heated, the air is sent into the car by the blower through various air outlets.
After we know the principle of heating, we need to check which parts are out of order, which will lead to the failure of air conditioning and heating system. First, check whether the antifreeze of the vehicle is sufficient. If there is not enough antifreeze, the air conditioner will not be hot.
Next, check whether the heater tank and pipeline in the heating system are damaged or blocked, so that antifreeze cannot pass through these two parts, and the heat of the engine is not transferred to the cab, so it does not generate heat.