Yamaha 2002 TDM900 Service Manual page 438

EAS00797
2. The tail/brake light fails to come on.
1. Tail/brake light bulb and socket
S Check the tail/brake light bulb and socket
for continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS"
S Are the tail/brake light bulb and socket OK?
YES
2. Brake light switches
S Check the brake light switches for continuity.
Refer to "CHECKING THE SWITCHES".
S Is the brake light switch OK?
YES
NO
Replace the
tail/brake light bulb,
socket or both.
NO
Replace the brake
light switch.
8-38
SIGNALING SYSTEM
3. Voltage
S Connect the pocket tester (DC 20 V) to the
tail/brake light coupler (wire harness side)
as shown.
Positive tester probe ! yellow
Negative tester probe ! black
S Set the main switch to "ON".
S Pull in the brake lever or push down on the
brake pedal.
S Measure the voltage (DC 12 V) of yellow
on the tail/brake light coupler (wire harness
side).
S Is the voltage within specification?
YES
This circuit is OK.
ELEC
1
2
1
NO
The wiring circuit
from the main switch
to the tail/brake light
coupler is faulty and
must be repaired.