Yamaha 2003 YFZ450S, Service Manual

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ELEC
SIGNAL SYSTEM
EBS01075
CHECKING THE SIGNALING SYSTEM
EBS01076
1. The tail/brake light fails to come on.
YES
NO
YES
NO
YES NO
EBS01077
2. The neutral indicator light fails to come on.
YES
NO
1. Tail/brake light bulb and bulb socket
• Check the tail/brake light bulb and bulb
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the tail/brake light bulb and bulb
socket OK?
Replace the tail/
brake light bulb, bulb
socket or both.
2. Brake light switches
• Check the brake light switches for continu-
ity.
Refer to “CHECKING THE SWITCHES”.
• Is the brake light switch OK?
Replace the brake
light switch.
3. Voltage
• Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side)
as shown.
Positive tester probe
→
yellow
1
Negative tester probe
→
black
2
• Set the main switch to “ON”.
• Pull in the brake lever or push down on the
brake pedal.
• Measure the voltage (DC 12 V) of yellow
1
on the tail/brake light coupler (wire har-
ness side).
• Is the voltage within specification?
This circuit is OK. The wiring circuit
from the main switch
to the tail/brake light
coupler is faulty and
must be repaired.
1. Neutral indicator light bulb and socket
• Check the neutral indicator light bulb and
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the neutral indicator light bulb and
socket OK?
Replace the neutral
indicator light bulb,
socket or both.
Y L
B
L Y
B
1
2