Im trying to power a computer fan with batteries for a project. The fan wasn't turning so i tried upping the voltage. Ive tried one two and tree 9 volt batteries in series to make it turn. It worked best with two but the bizarre thing is that ever second or so it stops and sometimes switches direction. the fan has 3 leads red white and black. im powering red and back is ground the whit i think is a fan speed information wire of some kind. im not really sure. Any one have any ideas?