Yamaha YP400T Service Manual page 363

2. Voltage
• Connect the pocket tester (DC 20 V) to the
front turn signal/position light coupler (wire
harness side) as shown.
È Front turn signal/position light (left)
É Front turn signal/position light (right)
Positive tester probe → blue 1
Negative tester probe → black 2
È
B L
Ch
B Ch L
2 1
• Set the main switch to "ON".
• Measure the voltage (DC 12 V) of blue 1
on the front turn signal/position light cou-
pler (wire harness side).
• Is the voltage within specification?
YES
This circuit is OK.
É
B L
Dg
B Dg L
2 1
NO
The wiring circuit
from the main switch
to the front turn sig-
nal/position light cou-
pler is faulty and
must be repaired.
8 - 32
LIGHTING SYSTEM
EAS00792
5. The license plate light fails to come on.
1. License plate light bulb and socket
• Check the license plate light bulb and
socket for continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
• Are the license plate light bulb and socket
OK?
YES
2. Voltage
• Connect the pocket tester (DC 20 V) to the
rear turn signal/license plate light coupler
(wire harness side) as shown.
Positive tester probe → brown 1
Negative tester probe → black 2
• Set the main switch to "ON".
• Measure the voltage (DC 12 V) of brown
1 on the rear turn signal/license plate light
coupler (wire harness side).
• Is the voltage within specification?
YES
This circuit is OK.
– +
ELEC
NO
Replace the license
plate light bulb,
socket or both.
Ch Dg
Dg Ch
B L/R Br B
1 2
NO
The wiring circuit
from the main switch
to the rear turn sig-
nal/license plate light
coupler is faulty and
must be repaired.