Yamaha T135SE Service Manual page 321

4. The auxiliary light fails to come on.
1. Meter light bulb and socket
9Check the meter light bulb and socket for
continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
9Are the meter light bulb and socket OK?
YES
2. Voltage
9Connect the pocket tester (AC 20 V) to the
auxiliary light coupler (wire harness side) as
shown.
Positive tester probe → → blue 1 1
Negative tester probe → → black 2 2
9Set the main switch to "ON".
9Start the engine.
9Measure the voltage (AC 12 V) of blue lead
terminal 1 on the auxiliary light coupler
(wire harness side).
9Is the voltage within specification?
YES
This circuit is OK.
YamahaT135.COM
Yamaha T135 Service Manual
NO
Replace the auxil-
iary light bulb,
socket or both.
1
[L]
L L
Ch
Ch
B B
1
[R]
L
L
Dg
Dg
B
B
NO
Replace the rectifi-
er/regulator.
LIGHTING SYSTEM
8-29
ELEC