Yamaha YFZ450S 2003 Service Manual page 361

3. Voltage
• Connect the pocket tester (DC 20 V) to the
indicator light connector (wire harness
side) as shown.
Positive tester probe → red/black 1
Negative tester probe → white/blue 2
• Set the main switch to "ON".
• Measure the voltage (12 V) of red/black 1
and brown 2 at the indicator light coupler.
• Is the voltage within specification?
YES
4. Diode
• Remove the diode from the coupler.
• Connect the pocket tester (Ω × 1) to the
diode terminals as shown.
• Check the diode for continuity as follows.
Positive tester probe →
blue/black 1
Negative tester probe →
white/blue 2
Positive tester probe →
white/blue 2
Negative tester probe →
blue/black 1
NO
The wiring circuit
from the main switch
to the indicator light
connector is faulty,
repair it.
Continuity
No
continuity
SIGNAL SYSTEM
NOTE:
When you switch the tester's positive and
negative probes, the readings in the above
chart will be reversed.
• Is the diode OK?
5. Start switch
• Check the start switch for continuity.
Refer to "CHECKING THE SWITCHES".
• Is the start switch OK?
The circuit is not
faulty.
8 - 38
ELEC
1
L/B
W/L
2
YES
Replace the diode.
YES
Replace the handle-
bar switch.
– +
NO
NO