2003 Yamaha YFM400FAR Kodiak Factory Service Manual, Page 343Get this manual
SIGNAL SYSTEM CHECKING THE SIGNAL SYSTEM 1.If the brake light fails to come on: 1.Bulb and bulb socket
Check the bulb and bulb socket for continuityCONTINUITY
NO CONTINUITY
Replace the bulb andor bulb socket
2.Brake light switches Refer to "CHECKING THE SWITCHES"CONTINUITY
NO CONTINUITY