Yamaha YP400T Service Manual page 361

3. Voltage
• Connect the pocket tester (DC 20 V) to the
headlight and meter assembly couplers as
shown.
È When the dimmer switch is set to "
É When the dimmer switch is set to "
Headlight
Positive tester probe →
Negative tester probe → black 3
Headlight coupler
DC 20V
+
É
High beam indicator light
Positive tester probe → yellow 4
Negative tester probe → black 5
Meter assembly coupler
Ch Dg Y
L
4
"
"
yellow 1 or green 2
È
2
G
Y B
3
1
R/W R/G G
Y/L B/L Gy B
5
8 - 30
LIGHTING SYSTEM
• Set the main switch to "ON".
• Start the engine.
• Set the dimmer switch to "
• Measure the voltage (DC 12 V) of yellow
1 (green 2) on the headlight coupler and
yellow 4 on the meter assembly coupler
(wire harness side).
• Is the voltage within specification?
YES
This circuit is OK.
EAS00789
2. The meter light fails to come on.
1. Meter light bulb and socket
• Check the meter light bulb and socket for
continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
• Are the meter light bulb and socket OK?
YES
– +
ELEC
" or " ".
NO
The wiring circuit
from the main switch
to the headlight cou-
pler or meter assem-
bly coupler is faulty
and must be
repaired.
NO
Replace the meter
light bulb, socket or
both.