2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 337Get this manual
LIGHTING SYSTEM
3.Main switch
C0NTINUITY INCORRECT
Refer to "SWITCH INSPECTION"CORRECT 4.Lights switch Refer to "SWITCH INSPECTION"CORRECT Lights switch is faulty, replace the handlebar switch (left)Replace the main switchINCORRECT