Yamaha YQ50 Service Manual page 175

2. The tail light does not work.
1. Bulb and socket
• Check the bulb and socket for continuity.
2. Brake switch
• Disconnect the brake switch leads from the
wire harness.
• Check for continuity between:
Brown Q and Green / Yellow W
ON (Pull in)
OFF (Free)
3. Voltage
• Connect the pocket tester (DC20V) to the
socket.
Pocket tester (+) lead © Green / Yellow Q
Pocket tester (-) lead © Black W
• Turn the main switch to "ON".
• Pull the brake lever.
• Check the voltage (12V) between " Green /
Yellow" Q and "Black" W.
LR
LR
GY
GY
B
B
Circuit is in good condition.
CONTINUITY
Br GY
Br GY
CONTINUITY
MEETS
SPECIFICATION
SIGNAL SYSTEM
NO CONTINUITY
Replace bulb or socket.
NO CONTINUITY
Brake switch is defect © Replace.
OUT OF SPECIFICATION
There is a defect in the wire harness between
the main switch and the tail light socket
© Repair.
8-25
ELEC