Electric fan will not stop running

[routeg35]

Hi I own a 2001 740I Sport. two days ago I notice a noise coming from front of car. After check I realize electric fan that is located in front of condensor for air condition and radiator is running constant while car is running. My question? can the switch that control the fan be broken or is it a sensor. I need help in trouble shooting this problem. And direction on where sensor or fan switch is located. Thank You

[thejlevie]

I think the aux fan on this car may be controlled by a PWM signal from the DME. If that's the case the cause of the fan running all the time, regardless of engine temperature, would be a failure of the controller in the fan or a problem in the DME.

[rennfahrer]

you may want to try the temperature switch that goes into the radiator
cheap and easy

[cpundsack]

This happened on my 99 M3, and I had a faulty relay . . . .

[nathan56989]

This fan will run at all times the ac is on as well. Does it shut off when the vehicle is turned off? Have you checked it to see if it turns off when the ac is turned off? Could be a faulty fan. (not very uncommon) IF it is only on when the ac is on that is normal. reguardless of engine temperature. also keep in mind that if the outside temp is below somewhere around 35 defrees your ac will not work. that is also normal.
Hope this helps.