2007 Yamaha Apex Factory Service Manual, Page 269Get this manual

2007 Yamaha Apex Factory Service Manual, Page 269

SIGNAL SYSTEM TROUBLESHOOTING BRAKE LIGHT DOES NOT COME ON Check the tailbrake light bulb(s)Refer to "LIGHTING SYSTEM"OK
Check the stator coil and pickup coilOK OUT OF SPECIFICATION Check the batteryRefer to "BATTERY INSPECTION" in CHAPTER 2OK
OUT OF SPECIFICATION Replace andor charge the batteryRefer to "BATTERY INSPECTION" in CHAPTER 2 Check the main switchRefer
to "IGNITION SYSTEM"OK FAULTY Replace the main switch Check the brake light switchOK FAULTY Replace the brake light switch