2006-2008 Yamaha Snowmobiles Apex/Attak Factory Service Manual, Page 285Get this manual
CARBRETER HEATER SYSTEM
CARBURETOR HEATER RELAY 1Inspect: Carburetor heater relay Inspection steps: Disconnect the carburetor heater relay from the couplerS Connect the pocket tester1) and battery (12 V) to the carburetor heater relay terminals as shownPositive battery terminalBlueRed Negative battery terminalBrownYellow Positive tester probeBlackYellow Negative tester probeRedWhite If carburetor heater relay does not have continuity between the blackyellow and redwhite terminals, replace it