2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 336Get this manual
LIGHTING SYSTEM EB805010
TROUBLESHOOTING IF THE HEADLIGHT, TAILLIGHT ANDOR METER LIGHT FAIL TO COME ON: Procedure Check: 1.Fuse (main) 2.Battery 3.Main switch
4.Lights switch 5.Wiring connections (the entire lighting system)
NOTE: Remove the following part(s) before troubleshooting: 1)Seat 2)Front carrier 3)Front fender panel Use the following special tool(s) for troubleshooting