2002 Yamaha YFM660 Grizzly factory service and repair manual, Page 374Get this manual
LIGHTING SYSTEM EB805020
CHECKING THE LIGHTING SYSTEM 1.If the headlights fail to come on: 1.Bulb and bulb socket
NO CONTINUITY
Check the bulb and bulb socket for continuityReplace the bulb andor bulb socketCONTINUITY