The controller has a Hi/Lo temp setting. You can set through hiJack what the hysteresis is. It's config'd through the .ini file. There's a post from Mark about it in our thread in the for sale section....

As for slowing the fan down... sometimes that's not the best idea. Some DC fan's don't like too low a voltage and then they stall. I played with some once like that and some don't restart without full off/on voltage again... So, it can be done, but without a controller like the max 6651 which has a tach feedback, you don't know if you've stalled out the motor.

Either way - I thought about that and considering I drive a jeep, I wouldn't really ever hear the fan anyway... so I opted for full on/off. There's another design floating around for those who want variable speed.

Thankfully, you have a choice! If you use the other design, more power to ya.

Enjoy...

-Ben