The automobile electronic fan is controlled by the temperature controller. When the water temperature rises to the upper limit, the temperature controller turns on the power and the fan starts to work. When the water temperature drops to the lower limit, the temperature controller turns off the power and the fan stops working.

The high and low speed of the automobile electronic fan is controlled by the "only" thermal switch (F18). This switch has two gears and is installed on the water tank to detect the water temperature. It sends two gear signals to j293, and j293 turns on different open circuits to control the high and low speed of the electronic fan. Turn on the air conditioner. Both fans should turn. However, it should be noted that air conditioning and electronic fan are two relatively independent systems controlled by two computers, named j301 (air conditioning) and j293 (electronic fan). J301 only sends a signal to j293 to force 2 electronic fans to start. In addition, there is not much correlation.

When the electronic fan motor works, the current is large, the requirements for the wires used are high, and it will generate a certain amount of heat. The material specification used for the imitation parts is low and the heat generation is large, which is easy to lead to vehicle spontaneous combustion. When the electronic fan works, it rotates at high speed, which has high requirements for manufacturing process. The dynamic balance of the imitation part is difficult to meet the design requirements. It has a large vibration when installed on the vehicle, and it will become loose due to vibration after long-time operation.