1997 Yamaha YFM600FWAK ATV Service Manual, Page 302Get this manual
SIGNAL SYSTEM
3.Voltage Connect the pocket tester (DC 20 V) to the bulb socket connectorTester (+) lead -7 Brown lead CD Tester (-) lead -7 Frame ground
Turn the main switch to "ON" Check for voltage (12 V)
OUT OF SPECIFICATION
MEETS SPECIFICATION