Radiator fan wiring?

I feel rather stupid even asking this question but I can't seem to figure out why there are so many wires on my electric fan. I have a Calsonic dual fan and shroud setup that I got from some fairies I found dancing in a field. Who knows what sort of vehicle they tore it off of.

Anyway, there are two connectors per motor. One single-wire connector and one triple-wire connector. Through trial and error I discovered that that the yellow wire coupled with either the blue or green will make the fan turn. Reversing polarity obviously reverses flow.



At first I thought maybe the different leads created different RPMs but according to my calibrated eyes and ears it doesn't seem to make a difference.

So push come to shove I can just wire up one of the sets and be done with it. But the curiosity in me wants to figure out what's up with those other wires.

Ideas?

No, that's a good thought. I'll try it.

One of my friend's suggests that one wire is for the fan operation while the car is turned off and the other is for while the car is running. While this is a decent suggestion, I can't see why they'd use two power wires when a single would be sufficient. Every scenario I can dream up can be solved by using a simple relay prior to the fan and thus eliminating the need for FOUR friggin' wires!