Yamaha YQ50 Service Manual page 178

This circuit is in good condition.
4. The "OIL" indicator light does not work.
1. Bulb and socket
• Check the bulb and socket for continuity.
2. Oil level switch
• Disconnect the oil level switch from the oil
tank.
• Connect the pocket tester (Ω x 1) to the oil
level switch.
Pocket tester (+) lead © Terminal Q
Pocket tester (-) lead © Terminal Q
• Check the switch for continuity.
Float Good
position condition
HIGH
LOW
O : Continuity X : No continuity
A
B
CONTINUITY
Bad
condition
X O X
O X X
MEETS
SPECIFICATION
SIGNAL SYSTEM
NO CONTINUITY
Replace bulb or socket.
O
O
DOES NOT MEET SPECIFICATION
Replace oil level switch is defect.
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