4x4 Problem

[aronbayev]

I own a 2002 chevy s 10. 2 years ago my 4x4 broke down. I brought the car to the dealership. They told that the control madule needs to be replaced and the transfer case motor too. 1500 dollars and some time later I try the 4x4 at the first snow fall. The shift on the fly would not work. Back to the dealership. They replace evrything. Still when I use the 4x4 it shuts down after shifting in and out of 4x4 2 or 3 times and the shift on the fly goes blank and I need to unplug the battery to reset the computer. Then it works for 2 or 3 times and then we are back to where I was before.

Help me solve this problem.