Checking The Lighting System - Yamaha YFZ450S 2003 Service Manual

EBS01069
3. Wiring
• Check the entire lighting system's wiring.
Refer to "CIRCUIT DIAGRAM".
• Is the lighting system's wiring properly
connected and without defects?
YES
Check the condition
of each of the lighting
system's circuits.
Refer to "CHECK-
ING THE LIGHTING
SYSTEM".
EBS01070

CHECKING THE LIGHTING SYSTEM

1. The headlights fail to come on.
1. Headlight bulb and socket
• Check the headlight bulb and socket for
continuity.
Refer to "CHECKING THE BULBS AND
BULB SOCKETS".
• Are the headlight bulb and socket OK?
YES
NO
Properly connect or
repair the lighting
system's wiring.
NO
Replace the head-
light bulb, socket or
both.
LIGHTING SYSTEM
2. Voltage
• Connect the pocket tester (AC 20 V) to the
headlight couplers as shown.
È When the light switch is set to "LO"
É When the light switch is set to "HI"
Headlight coupler (wire harness side)
Headlight
Positive tester probe →
Negative tester probe → black 3
AC20V
• Set the main switch to "ON".
• Start the engine.
• Set the light switch to "LO" or "HI".
• Measure the voltage (AC 12 V) of yellow
1 or green 2 on the headlight coupler
(wire harness side).
• Is the voltage within specification?
This circuit is OK.
8 - 31
ELEC
yellow 1 or green 2
É
2 1
G Y
B
3
È
YES
Replace the rectifier/
regulator.
– +
NO