Why does the car air conditioning cooling fan keep running at high speed?

[ArielRose]

When the temperature is too high, it operates at high speed, and when the temperature is normal, it operates at low speed for cooling, which is a normal phenomenon. Related introductions are as follows: 1. Classification: According to the direction of coolant flow in the radiator, radiators can be divided into two types: longitudinal flow and cross flow. According to the structure of the radiator core, radiators can be divided into tube-fin radiator cores, tube-belt radiator cores, and plate-type radiator cores. 2. Material: There are mainly two types of car radiators: aluminum and copper. The former is used for general passenger cars, while the latter is used for large commercial vehicles. The materials and manufacturing technology of car radiators are developing rapidly. While aluminum radiators are gradually replacing copper radiators in the field of cars and light vehicles due to their obvious advantages in material lightweighting, the manufacturing technology and process of copper radiators have made significant progress. Copper brazed radiators have obvious advantages in engine radiators for buses, construction machinery, and heavy trucks.

[ORhett]

In my car repair experience, a common issue is the high-speed rotation of the air conditioning fan. This is usually caused by a stuck or short-circuited fan control relay. The relay is responsible for adjusting the fan speed, and once the internal contacts stick together, the fan will continue to run at high speed. A faulty temperature sensor can also mislead the system, causing the fan to always run at high speed. During inspection, start the engine and turn on the air conditioning, then use a multimeter to test the relay terminals to see if they are stuck in the closed position. If replacing the relay doesn’t work, check whether the sensor signal is normal. It could also be due to excessive pressure in the air conditioning system, forcing the fan to run at high speed to cool and protect the components. In this case, check the refrigerant level and the cleanliness of the condenser. A fan running continuously at high speed increases the burden on the battery and reduces its lifespan, so professional repair is recommended in a timely manner. During regular maintenance, pay attention to cleaning the engine compartment to avoid moisture or aging and short circuits in the circuit components, which can prevent similar faults.

[VonAutumn]

As an ordinary car owner, I once encountered the issue of loud noise from the high-speed rotation of the air conditioning fan. At that time, I discovered that it was caused by a clogged radiator with excessive dust, leading to poor heat dissipation and the fan spinning wildly. After cleaning the radiator grille, it returned to normal. The fan speed should automatically adjust, but prolonged high-speed operation indicates a system imbalance, such as insufficient coolant or sensor failure, which can also cause similar problems. Self-inspection method: Turn off the air conditioning and wait a few minutes to see if the fan slows down; if it doesn't stop, pull out the fan fuse for a brief test. High-speed fan rotation not only consumes more fuel but also affects the driving experience. In my case, the battery was almost drained due to delayed handling. I recommend cleaning the front radiator area during regular car washes and paying attention to changes in fan noise to avoid major repairs.

[JulianaLee]

Having driven for decades, I know that a high-speed fan rotation should be taken seriously. The most common causes are relay failure or circuit short circuits. When the fan control circuit ages, relays are prone to sticking, preventing the fan from slowing down. It could also be due to a faulty air conditioning pressure sensor. During inspection, visually check or feel the relay temperature—if it's too hot to touch, it indicates a problem. Regularly cleaning the air conditioning condenser and removing debris from the fan blades can alleviate symptoms. Continuous high-speed fan operation increases wear and may affect other electronic components. For safety, if any issues are detected, stop the car for inspection or seek repairs immediately to avoid further damage.

[Lucille]

As a car enthusiast, I understand that high-speed fan operation is often caused by control module failure or sensor errors. The fan speed is managed by the control unit, and a faulty relay signal output can cause the fan to run at high speed continuously. You can try a simple DIY: start the engine and turn on the air conditioning to observe the fan's behavior; gently tap the relay housing to check for looseness or sticking. Clearing obstructions in front of the condenser might help. If the control issue persists, the high-speed fan will consume a large amount of electricity, affecting battery performance. Ensure regular maintenance of your vehicle's air conditioning system, including checking for refrigerant leaks and cleaning the fan.

[FernandoFitz]

I believe that the fan continuously running at high speed involves deep-seated control faults. The welding of the fan relay contacts or the air conditioning pressure switch being stuck in a high position can cause the fan to run at high speed constantly. Damage to temperature sensors, such as the coolant sensor, can also mislead the system into thinking there is high temperature, prompting high-speed cooling. Use a multimeter to check the circuit continuity or a diagnostic tool to see if there are any fault codes indicating issues. Control unit software errors require professional repair; otherwise, the fan running at high speed will increase engine fuel consumption and noise. Maintaining the proper amount of refrigerant is crucial to avoid abnormal pressure that triggers abnormal fan operation, making timely maintenance key.