aux fan switch

[mars@xxxxxxxxxxxxxxx (mars)]

The E34 car's radiator has a aux fan switch, it maybe when the water is
91 celsius to active aux fan slow, when the water go to 99 celsius, this
will cause the aux fan fast.
I pull out the switch's connector, I find three pins in the cap with the
1-2-3 number.
I think they maybe one for ground, another control slow fan run, the
other for fast fan run.
Does anyone know they correctly?

Thanks
Tsai-Pao Hsu

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