What is the function of the electric fan? Does it do any more than blow dust particles out the back of the rig? If I don't run it will dust fill up and plug the vortexes. I have a switch on mine so I can shut it off while leaving the switch on acc so that the map stays on. I tend to forget to turn it back on. I've had heavy equipment with vortex separators that don't have any electric blower fans so I'm skeptical of it's necessity.