Fans have no idea what's sending them the juice. All PWM does is chop teh supply voltage to the fan to control speed. basically it's on/off/on/off from the controller with longer ON times when it needs more speed. No reason any 12v PWM controller with sufficient current capacity couldn't be used to do this. Tons of cheap ones on amazon.
The fans I'm referring to have 3 wires; large gauge hot and ground, then a much smaller gauge 3rd wire. They will not run with normal positive and negative hooked up. This is the same for all new fans I can find . Apparently the small Dia wire needs a signal.....
