Yes there is a fan controller that works like a blower resistor, there has been a lot of problems with these units, since the poor design of the blower motor inlet (under cowl) allows water to get in, thus causing corrosion in the module and shorting out. Or your blower motor could be going bad as well, like mentioned before do a thread search for some more possible reasons and or repairs. I hope this gets you going in the right direction.