Yamaha YJ50RAP Service Manual page 210

4. Voltage
• Connect the pocket tester (DC 20 V) to the
horn connector at the pink terminal as
shown.
Positive tester probe → pink 1
Negative tester probe → ground
• Set the main switch to "ON".
• Measure the voltage (12 V) of pink 1 at
the horn terminal.
• Is the voltage within specification?
YES
Repair or replace
the horn.
EAS00798
2. 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.
• Are the tail/brake light bulb and socket
OK?
YES
NO
Replace the horn.
NO
Replace the tail/
brake light bulb,
socket or both.
SIGNALING SYSTEM
2. Brake light switches
• Check the brake light switches for continu-
ity.
Refer to "CHECKING THE SWITCHES".
• Is the brake light switch OK?
3. Voltage
• Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side)
as shown.
Positive tester probe → green/yellow 1
Negative tester probe → black 2
• Set the main switch to "ON".
• Pull in the brake levers.
• Measure the voltage (12 V) of green/yel-
low 1 on the tail/brake light coupler (wire
harness side).
• Is the voltage within specification?
This circuit is OK.
7 - 33
ELEC
YES
Replace the brake
light switch.
1
L L
Y G/Y
B B
2
YES
The wiring circuit
from the
switch to the tail/
brake light coupler
is faulty and must
be repaired.
– +
NO
NO
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