Since my net is back up, I'll tell.
The tracker uses two leds that produce electricity when in the sun(like a solar cell). The tracker senses the two voltages and when one is higher than the other, it moves that direction. At night, when there is no voltage, it goes back to east. It keeps driving the motor back all night, so your motor must have stop points on them, so it wont unscrew itself. If you put your hand over it, it would go back east. As soon as the sun comes up and give the leds some power, it tracks.