help with coolant fan switch wiring

I picked up a BMW coolant fan switch for my e-fan conversion because the switch is a dual temp switch and I wanted something that would keep the fan off until the engine was up to operating temp for fast winter warm ups and second temp to kick in the high speed of the Ford Taurus fan.

I picked up the the switch and the pig tail from my local pull-a-part. What I need to know or rather advice on figuring out is which wire is what? Any suggestions one how to figure this out?