01 E320 Cooling Fan
 

Thanks in advance for taking the time to help me with my plight.

My mother has a 2001 E320 that has recently developed a curious condition. Upon starting the car, and about 10 seconds have passed, the electric cooling fan will slowly whir to life until it reaches maximum speed. For as long as the car is running, hot or cold, AC on or off, the fan will continue to power. Humming noisily as it goes.

My questions are:
What could be the culprit causing this problem?
In what area of the 320 would I find this part?

bump...:)

Bump to get an answer
 

I also have a 1996 W210 E300 with this same problem. Note, I also have a bad climate control head unit (dash buttons). I think that bad part might be sending power to keep my fans on when engine is on.
Thoughts?

To the first guy, the "normal" cause for problems with the fan on that model is the fan controller, which is sort of under the car's left headlight assembly (get at it through the splash guard, you can't see it by looking under the hood)
Gilly