Yamaha 2004 YP400, Service Manual, Page: 371 / 417

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ELEC
LIGHTING SYSTEM
EAS00781
TROUBLESHOOTING
Check:
1. main, headlights, signaling system, turn sig-
nal/hazard, and backup fuses
2. battery
3. main switch
4. dimmer switch
5. pass switch
6. storage box light switch
7. headlight relay 1
8. headlight relay 2
9. wiring connections
(of the entire lighting system)
NOTE:
_
• Before troubleshooting, remove the following
part(s):
1. storage box
2. front cowling
3. meter assembly
• Troubleshoot with the following special
tool(s).
EAS00738
YES NO
EAS00739
YES
NO
EAS00749
YES
NO
EAS00784
YES
NO
Any of the following fail to light: head-
lights, high beam indicator light, taillight,
license plate light, storage box light, aux-
iliary lights or meter light.
Pocket tester
90890-03112, YU-03112-C
1. Main, headlight, signaling system, turn sig-
nal/hazard, and backup fuses
• Check the main, headlight, signaling sys-
tem, turn signal/hazard, and backup fuses
for continuity.
Refer to “CHECKING THE FUSES” in
chapter 3.
• Are the main, headlight, signaling system,
turn signal/hazard, and backup fuses OK?
Replace the fuse(s).
2. Battery
• Check the condition of the battery.
Refer to “CHECKING AND CHARGING
THE BATTERY” in chapter 3.
Minimum open-circuit voltage
12.8 V or more at 20 °C (68 °F)
• Is the battery OK?
• Clean the battery
terminals.
• Recharge or
replace the battery.
3. Main switch
• Check the main switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the main switch OK?
Replace the main
switch/immobilizer
unit.
4. Dimmer switch
• Check the dimmer switch for continuity.
Refer to “CHECKING THE SWITCHES”.
• Is the dimmer switch OK?
The dimmer switch is
faulty. Replace the
left handlebar switch.