Yamaha 2009 YFM25RY Service Manual page 289

TROUBLESHOOTING
• Faulty battery
• Faulty rectifier/regulator
• Improperly grounded circuit
• Faulty main switch
• Faulty light switch
• Headlight bulb life expired
Tail/brake light does not come on
• Wrong tail/brake light bulb
• Too many electrical accessories
• Hard charging
• Incorrect connection
• Improperly grounded circuit
• Poor contacts (main or light switch)
• Burnt-out tail/brake light bulb
Tail/brake light bulb burnt out
• Wrong tail/brake light bulb
• Faulty battery
• Faulty rectifier/regulator
• Improperly grounded
• Faulty main and/or light switch
• Incorrectly adjusted rear brake light switch
• Tail/brake light bulb life expired
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