Chances are the actuator on the transfer case is coing bad. To determine if that is the problem, you need to check if the actuator is getting power when it isn't working. IF it is getting power, replace the actuator. If there is no power to it, then work your way back to the switch.
Let me know if you have other questions.
Joe
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Saturday, December 19th, 2009 AT 1:43 AM