Can someone please hlp with my transfer case ?

I have pulled my transfer case motor to check it out. At first my truck wouldn't go in 4 Hi. After playng with the switch ack and forth the truck was stuck in 4 Low. I took the t--case motor of and manually put the truck back in 4 Hi.

How can I be sure the transfer case motor is bad ? It does not turn at all when I hit the buttons. I only hear clicking. Is there anything else that would make the transfer case motor not move ?

4 Wheel drive works fine if I manually change it on hte transfer case with a wrench.


Thanks,
Branden

The motor is thermatically controlled and takes a few seconds (worse when colder out) to engage. There is a gas filled cylinder inside that when switched on, the gas expands and engages 4wd. Hope this helps.