1987-2009 Yamaha ATV YFM350X Warrior Raptor Service Manual, Page 220Get this manual
CHECKING OF BULBS ELEC
2Check the bulb terminals for continuity
Checking steps: Set the pocket tester selector to the "0 xl" Connect the tester leads to the respective bulb terminalsTake for example 3-terminal bulb as shown leftFirst check the continuity beand (2) terminals by connecting tween the the tester+lead to the terminal and the tester-lead to the (2) terminalThen check the continuity between the Q) and terminals by connecting the tester+) lead still to the Q) terminal and the tester (-) lead to the terminalIf the tester shows" 00" in either case, replace the bulb