Cooling Fan

[iamzen]

The car is 2003 Z4 3.0i roadster, M84.
The radiator fan stopped working, that is, it does not go on when the car reaches operating temperature.
Either the fan or some control circuit is at fault. To diagnose, I removed the fan from the car.
The power is brought to the fan via a three contact connector. Two of these wires are heavy gauge and provide 12 V DC even when the ignition is off.
I am guessing that the third wire controls the fan on/off state.
For testing I have connected 12 V power to the two power prongs on the connector on the fan assembly.
Then I have connected +12 V to the third prong and nothing happened. I expected that the fan would spin if it was in a working order.

I would like to determine that the fan is bad before buying a replacement.

Has anyone dealt with this kind of problem?

BTW, I bought an electronic shop manual, TIS, and find it rather disappointing, since it seems to contain rather rudimentary information only. Perhaps, I am not clever enough to find in it what I am looking for. I expected to find electical diagrams, but found none.
Anyone knows of a good shop manual?

Thanks in advance,
Zen

 

[Ewazix]

I can't find it right now but have previously read reports concerning BMW fans from this era failing and even causing fires. From memory I think it was a magnet in the motor coming loose and jamming or restricting the rotation of the motor (a jammed motor can get hot, potentially very hot).