2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 199Get this manual
ELECTRICAL Fan Motor Circuit Operation
Power is supplied to the fan switch once the key switch is turned "ON"When the coolant temperature in the radiator reaches 190 (88 C), the fan switch closes and powers the fan motor via the OrangeBlack wireThe fan motor ground path is provided through the Brown harness wire1234Disconnect the harness from the switchPlace suitable container below the radiator to catch coolant upon switch removalApply commercially available thread sealer to the threads of the new thermal switchInstall switch and torque to 18 ftlbs(24 Nm)
CAUTION
Keep hands away from fan blades during operationSerious personal injury could resultNOTE: The fan motor may not operate or operation may be delayed if coolant level is low or if air is trapped in the cooling systemBe sure cooling system is full and purged of airRefer to Chapter "Maintenance" for cooling system information