Yamaha YFM400FAR Service Manual page 349

5.If the four-wheel drive indicator light fails to
come on:
1.Bulb and bulb socket
Check the bulb and bulb socket for
G
continuity.
2.Voltage
Connect the pocket tester (DC 20 V) to the
G
bulb socket lead.
Tester (+) lead → Brown/Red terminal 1
Tester (–) lead → White terminal 2
Turn the main switch to "ON".
G
Check the voltage (12 V).
G
This circuit is not faulty.
CONTINUITY
MEETS
SPECIFICATION
9 - 42
SIGNAL SYSTEM
NO CONTINUITY
Replace the bulb and/or bulb socket.
OUT OF SPECIFICATION
The wiring circuit from the main switch to the
bulb socket connector is faulty, repair it.
– +
ELEC