Yamaha TW125 1999 Service Manual page 270

EAS00797
2. A tail/brake light fails to come on.
1. Tail/brake light bulb and socket
S Check the tail/brake light bulb and socket for
continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
S Are the tail/brake light bulb and socket OK?
YES
2. Brake light switches
S Check the brake light switches for continuity.
Refer to "CHECKING THE SWITCHES".
S Is the brake light switch OK?
YES
3. Voltage
S Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side) as
shown.
Tester positive probe ! yellow
Tester negative probe ! black
NO
Replace the tail/brake
light bulb, socket or
both.
NO
Replace the brake lig-
ht switch.
1
2
SIGNAL SYSTEM
S Set the main switch to "ON".
S Pull in the brake lever or push down on the
brake pedal.
S Measure the voltage (12 V) of yellow at the
tail/brake light coupler (wire harness side).
S Is the voltage within specification?
YES
This circuit is OK.
EAS00799
3. A turn signal light, turn signal indicator light
or both fail to blink.
1. Turn signal light bulb and socket
S Check the turn signal light bulb and socket for
continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
S Are the turn signal light bulb and socket OK?
YES
3. Turn signal switch
S Check the turn signal switch for continuity.
Refer to "CHECKING THE SWITCHES".
S Is the turn signal switch OK?
YES
7-31
ELEC
NO
The wiring circuit fr-
om the main switch to
the tail/brake light co-
upler is faulty and
must be repaired.
NO
Replace the turn sig-
nal light bulb, socket
or both.
NO
Replace the left han-
dlebar switch.