The right fan is powered directly off the battery and is manually turned on and off with a handlebar power switch. The left fan is wired to the factory harness and turns on and off automatically...
YFZ450R EFI 2009-2013 Dual Fan Kit. The right fan is powered directly off the battery and is manually turned on and off with a handlebar power switch. The left fan is wired to the factory harness and turns on and off automatically from the factory fan temperature sensor.