The function of the automotive electronic fan
Cooling the engine and assisting the air conditioning system
The main function of the automotive electronic fan is to cool the engine and assist the air conditioning system. Specifically, it includes:
Cooling the engine: By reducing the temperature of the water tank, it cools the engine block and transmission, preventing overheating and ensuring the engine's performance and lifespan.
Assisting the air conditioning system: It cools the air conditioning condenser, accelerating the coolant circulation in the cooling mode and improving the cooling efficiency; in heating mode, it assists in delivering warm air to the interior of the vehicle.
The core symptoms of a fan failure in a car include abnormal increase in water temperature (high temperature alarm on the dashboard), abnormal fan operation or abnormal fan speed, abnormal noise (such as friction sounds or clicks) during operation, and significant decline in air conditioning cooling efficiency. The specific manifestations are as follows:
Continuous increase in water temperature: The pointer of the dashboard water temperature gauge exceeds the normal range of 90°C or the high-temperature warning light illuminates, especially more obvious at idle.
Abnormal fan operation: By opening the engine compartment for inspection, the fan is completely not turning, running at an excessively low speed, or operating at a single speed (always at high speed or low speed).
Abnormal noise: The fan emits sharp friction sounds, periodic clicks, or buzzing noises, indicating blade deformation or bearing wear.
Significant decline in air conditioning cooling efficiency: After turning on the air conditioning, the outlet temperature rises (above 10°C), and the water temperature also rises simultaneously, due to insufficient cooling of the condenser.
Consequences: Engine power decreases, fuel consumption increases, and in severe cases, there may be a burnt smell or traces of coil burnout.
Common causes of a non-operating electronic fan in a car include poor contact of the air conditioning switch, motor or bearing failure, insufficient water temperature, damaged fuses or relays, and wiring problems.
Control and sensor failure
Temperature control switch or sensor failure: Unable to accurately detect water temperature, resulting in the fan not starting at high temperatures (such as a water temperature sensor failure or thermostat jamming).
ECU or control module failure: Program errors or hardware damage in the electronic control unit, blocking the fan start signal (requires professional equipment for diagnosis).
Mechanical and physical obstacles
Fan component damage:
Motor aging or bearing wear, resulting in insufficient power.
Blades blocked by dust/foreign objects or deformed, hindering rotation.
Cooling system blockage: Accumulated dirt on the radiator reduces cooling efficiency, indirectly causing the fan to stop.
Other key factors
Capacitor or starter failure: Capacitor capacity degradation or starter damage, affecting the initial operation of the motor.
Water pump idling or insufficient lubrication: Abnormal cooling fluid circulation (such as cracked impeller) or insufficient oil in the motor, increasing friction resistance.
Yes, a non-operating electronic fan can seriously affect driving safety.
The electronic fan is a key component of the engine cooling system. Its main function is to actively draw in cold air through the radiator and help cool the coolant, thereby maintaining the engine operating within the normal working temperature range. Once the fan fails, the cooling system's cooling capacity drops significantly, and the engine is highly prone to overheating, directly threatening driving safety.
Main effects include:
Engine overheating, reduced performance
The absence of fan operation leads to poor cooling, causing rapid increase in water temperature, and the engine behaves like "feverish", unable to operate normally, with reduced power output and increased fuel consumption.
High risk of mechanical damage
Long-term operation at high temperatures will cause the lubrication performance of the engine oil to decline, and the piston, cylinder block, and other key components to overheat and expand, severely causing "pulling cylinder", "bearing seizure", "cracking cylinder", and even engine failure.
Risk of "boiling" of the cooling fluid, with potential safety hazards.
High temperature causes the cooling fluid to boil, increasing pressure sharply, which may cause the water tank cover to spray liquid or the pipe to burst. Hot steam and liquid may scald people, especially dangerous when checking the engine compartment.
Significant decline in air conditioning cooling efficiency. The condenser of the air conditioning system also relies on fans for heat dissipation. If the fans stop rotating, the air conditioning will not be able to dissipate heat properly, resulting in a significant reduction in cooling efficiency and affecting driving comfort, especially during summer when fatigue from driving is exacerbated.
Frequent failures occur in critical scenarios
During traffic jams, waiting at red lights, or driving at low speeds, natural wind is insufficient to remove heat, and the role of the fan is particularly crucial. If the fan does not work at this time, the engine temperature will rise rapidly in a short period of time, and a failure is highly likely to occur.
Although in cold weather or short-distance driving, the engine heats up slowly and may not show overheating temporarily, this does not mean that it can be driven for a long time. Once the environmental temperature rises or the driving time extends, the risk will sharply increase.
Therefore, if you find that the electronic fan is not rotating, you should immediately stop the vehicle for inspection and do not continue driving. Common causes include:
Damaged or aged fan motor
Faults in the temperature control switch or water temperature sensor
Malfunctioning relays or blown fuses
Problems such as short circuits, open circuits, etc.
It is recommended to contact professional maintenance personnel for diagnosis and replacement as soon as possible to avoid causing greater losses.
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