2008 Arctic Cat ThunderCat ATV Service Manual, Page 97Get this manual
2With the ignition switch in the OFF position, connect the black tester lead to the black wire in the supply harness; then connect the red tester lead to the orange wire in the supply harness3Turn the ignition switch to the ON positionThe meter must show 12 DC volts4Connect the red tester lead to the whitered wire in the supply harnessThe meter must show 12 DC volts5Select the 4WD position on the front drive selector switch; then connect the red tester lead to the whitered wire in the supply harnessThe meter must show DC voltsNOTE: The 4WD icon on the LCD should illuminate 3Select the lock position on the differentialThe meter should drop to volts, and the front drive selector actuator switch should operate to engage 4-wheel driveNOTE: It may be necessary to rock the ATV slightly to engage the differential lock fullyNOTE: The 4WD and the LOCK icons on the LCD should illuminate
6Connect the red tester lead to the orange wire in the supply harnessThe meter must show 12 DC voltsNOTE: If the voltage readings are as specified and the actuator does not function correctly, replace the actuator (see Section 6)CD576