Yamaha YZF-R1 1998, Service Manual, Page: 385 / 418

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ELEC
SIGNALING SYSTEM
EB806411
2. A tail/brake light fails to come on.
YES
NO
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?
Replace the tail/
brake light bulb,
socket or both.
YES
NO
2.Brake light switches
• Check the brake light switches for conti-
nuity.
Refer to “CHECKING THE SWITCHES”.
• Is the brake light switch OK?
Replace the brake
light switch.
3.Voltage
• Connect the pocket tester (DC 20V) to
the tail/brake light coupler (wire harness
side) as shown.
Tester positive probe
→
yellow
1
Tester negative probe
→
black 2
YES
NO
• Set the main switch to “ON”.
• Pull in the brake lever or push down on
the brake pedal.
• Measure the voltage (12 V) of yellow at
the tail/brake light coupler (wire harness
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.
EB806413
3. A turn signal light, turn signal indicator
light or both fail to blink.
YES
NO
1.Turn signal light bulb and socket
• Check the turn signal light bulb and
socket for continuity.
Refer to “CHECKING THE BULBS AND
BULB SOCKETS”.
• Are the turn signal light bulb and socket
OK?
Replace the turn
signal light bulb,
socket or both.
YES
NO
2.Turn signal indicator light LED
• Check the LED of the turn signal indica-
tor light.
Refer to “CHECKING THE LEDs”.
• Is the turn signal indicator light LED OK?
Replace the meter
assembly.