Variable Electric Fan Control

[Ernest]

Is anyone running or has tried a variable speed fan controller?

http://www.dccontrol.com/introf0.htm

It always seemed to me having the option of variable control would be one of the major advantages of using an electric fan setup.

Thoughts?

[DesktopDave]

Looks interesting...I've wired up a few flip-flop circuits with relays, but that seems simple and robust.  Not somewhere I'd want to make a mistake...one overheat and an M42 head is done for.

Not to steal the thread but I always wanted to have that on the interior heater fan like the other BMWs...maybe grab a resistor blade and auto control from an e34 or e38...but I think the HVAC unit is too big for our console.  Maybe the e36 unit would work?  How much different can it be?