Yamaha 2002 CS50, Service Manual, Page: 184 / 204

ELEC
LIGHTING SYSTEM
8-25
• Set the main switch to “ON”.
• Start the engine.
• Measure the voltage (DC 12 V) of blue
on
the meter light coupler (wire harness side).
• Is the voltage within specification?
EAS00790
3. The tail/brake light fails to come on.
1. Tail/brake light bulb and socket
• Check the tail/brake light bulb and socket
for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”
• Are the tail/brake light bulb and socket OK?
2. Voltage
• Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side)
as shown.
Positive tester probe blue
Negative tester probe black
• Set the main switch to “ON”.
• Start the engine.
• Measure the voltage (DC 12 V) of blue
on
the tail/brake light coupler (tail/brake light
side).
• Is the voltage within specification?
EAS00791
4. The position light fails to come on.
1. Position light bulb and socket
• Check the position light bulb and socket for
continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”
• Are the position light bulb and socket OK?
2. Voltage
• Connect the pocket tester (DC 20 V) to the
position light coupler (wire harness side) as
shown.
Positive tester probe blue
Negative tester probe black
The wiring circuit
from the main
switch to the meter
light coupler is
faulty and must be
repaired.
This circuit is OK.
Replace the
tail/brake light bulb,
socket or both.
L
G/Y
B
1
2
Wiring circuit from
the main switch to
the tail/brake light
coupler is faulty and
must be repaired.
This circuit is OK.
Replace the posi-
tion light bulb,
socket or both.
L
B
L
B
1
2
YES
NO
YES
NO
YES
NO
YES
NO