2007-2008 Yamaha YFM700 Grizzly Factory Service Manual, Page 462Get this manual
2WD4WD SELECTING SYSTEM 8Differential gear motor Disconnect the differential gear motor coupler Remove the differential gear motor from the differential gear caseRefer to "FRONT CONSTANT VELOCITY JOINTS AND DIFFERENTIAL GEAR" in chapter Connect two size batteries to the differential gear motor terminals (as shown illustrations) Check that the pinion gear turns counterclockwise Check that the pinion gear turns clockwiseEBS01094
9Wiring connection Check the connections of the entire 2WD 4WD selecting systemRefer to "CIRCUIT DIAGRAM" Is the 2WD4WD system wiring properly connected and without defects? YES Replace the ECUNO Properly connect or repair the 2WD4WD selecting system wiring