What Causes a Car Fan to Keep Running?
2 Answers
Fan keeps running because the turbo fan is cooling down the turbo, which is a normal phenomenon. Fan delayed shutdown: During operation, the temperature distribution in the entire water channel is not uniform, and there are localized relatively high temperature points. When the water pump stops running, these heat cannot be dissipated, so the fan delays shutdown for the purpose of cooling, which is a normal phenomenon. Sensor commands the fan to run: Although the car is turned off, the temperature has not yet dropped. The electric fan is commanded by the sensor. In summer, if the car is parked under the sun, the electric fan will still rotate even if the car is not running, as long as the temperature reaches a certain degree. This situation is very normal.
I think the car fan running continuously could be caused by several common faults, especially when it keeps buzzing even after you turn off the engine. The most common issue is a faulty coolant temperature sensor, which is responsible for monitoring the engine temperature. If it's broken, it might mistakenly think the car is still hot, causing the fan to keep running. Additionally, if the fan relay gets stuck in the 'on' position, it can also lead to this situation; or there might be an internal short circuit in the control module, sending incorrect commands. From my experience, the air conditioning system can sometimes trigger the fan, especially in older car models. This is no small matter—a fan running for too long can quickly drain the battery, potentially leaving you unable to start the car, and it also increases the risk of wiring wear. When driving daily, it's advisable to check the dashboard temperature before turning off the engine. If it's abnormal, take the car to a repair shop immediately for diagnosis with the right tools—don’t let it turn into a bigger problem. Regular dust cleaning and heat dissipation can also help prevent such issues.
