Truck won't shift out of 4WD high. on 1997 Ford F-150

Had it out in the cold for a few months, battery died, but was recharged. It started shifting out of 4wd harder a couple of times since then, but now nothing at all. What could be possible problems and solutions? Any help is extremely appreciated!

Asked by for the 1997 Ford F-150
That thing is complicated, needs to go and be circuit tested to find the fault. Not as simple as telling you how, the issue has to be found.
1 more answer
try putting it in reverse and driving backwards for copuple hundred fett and as you get ready to stop put it in neutral