Yamaha XP500 Service Manual page 521

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.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
• Are the tail/brake light bulb and socket
OK?
YES
2. Brake light switches
• Check the brake light switches for continu-
ity.
Refer to "CHECKING THE SWITCHES".
• Is the brake light switch OK?
YES
NO
Replace the tail/
brake light bulb,
socket or both.
NO
Replace the brake
light switch(es).
SIGNALING SYSTEM
3. Voltage
• Connect the pocket tester (DC 20 V) to the
tail/brake light assembly coupler (wire har-
ness 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 (DC 12 V) of green/
yellow 1 on the tail/brake light assembly
coupler (wire harness side).
• Is the voltage within specification?
This circuit is OK.
8 - 43
ELEC
YES
The wiring
from the main switch
to the tail/brake light
assembly coupler is
faulty and must be
repaired.
– +
NO
circuit