Yamaha VMX12H Supplementary Service Manual page 336

LIGHTING SYSTEM
7-33
TESTS AND
The battery provides power for operation of
the headlight, taillight, and meter lights. If
none of the above fail to operate proceed further.
Low battery voltage indicates either a faulty
battery, low battery fluid level, or a defective
charging system.
Also check fuse condition. Replace any "open"
fuses. There are individual fuses for various
circuits (see complete Circuit Diagram).
NOTE:
Check each bulb first before performing the
following check.
CHECKS