Why does the car's cooling fan keep running?

[StAdaline]

There are several reasons why a car's cooling fan may continue to run: 1. If you notice the radiator fan running immediately after turning off the engine, wait for a while. The water temperature in the radiator decreases slowly, and the cooling fan may continue to operate for some time before stopping when the engine is first turned off. 2. If the car has completely cooled down but the fan still keeps running, there might be a fault in the cooling fan assembly or its wiring. 3. The fan in the car serves a cooling function. After parking, if the coolant temperature is too high, the vehicle's computer will automatically calculate the fan's speed and duration. The higher the temperature, the longer the fan will run to protect the engine, which is a normal phenomenon.

[StCayden]

I've driven quite a few cars and noticed that the cooling fan running non-stop is actually quite common. Usually, it's an issue with the cooling system. For example, a faulty coolant temperature sensor might incorrectly signal the fan to keep running, or insufficient coolant could cause the fan to work overtime to compensate for heat dissipation. Another possibility is a stuck fan relay—that little component in the fuse box—if it gets jammed, the fan won't stop. Electrical shorts or aging wiring harnesses can also cause similar issues, especially when temperatures are high. You should also check if any fuses are blown, as this can easily lead to fan malfunction. I always recommend checking these simpler components first. If the fan still doesn't stop after the engine cools down, take it to a repair shop immediately. Don't risk overheating the engine and damaging critical components—that repair bill could be hefty.

[AlainaMarie]

I recently encountered the issue of the fan running continuously. At first, I thought it was normal cooling, but later realized it was a malfunction. The cause is mostly in the control system—a faulty water temperature sensor can misjudge the temperature, causing the fan to keep running. It could also be a stuck fan switch or relay, such as when relay contacts are burned and fused together, keeping it in the on position. Circuit short circuits and overheating are also factors, leading to unstable power supply and continuous operation. Additionally, low coolant levels due to leaks can cause the fan to run non-stop in an attempt to compensate for cooling. I recommend first checking the radiator fluid level and dashboard warning lights. If simple adjustments don’t stop it, consult a professional technician to test the circuit with a multimeter. Early repairs can save the battery and prevent additional wear.