I had just recently had a whole new cooling system (thermostat, radiator, water pump, etc.) put in my M3. Now, forgive me if this is a dumb question, I really dont know much about cars mechanicaly. As I understand it the fan in front of the engine is on "low" speed when the ac is on, and should switch to "high" speed if the temp gets to hot. Well the thing is the fan is always spinning, even when the AC is off. The car could have been sitting over night, and when I wake up and start the car (AC is off) the fan starts spinning instantly. Is this normal for the fan to ALWAYS be on, or do you think my mechanic screwed something up when the coolant system was replaced?