Stuck in 4 Wheel Drive Gear 1989 Jeep Wrangler was stuck in sand. Shifted to 4 wheel drive and now cannot switch back to AWD. Any suggestions?

that is because you have Part time 4wd? (what do you have)?
and must not drive on pavement free of ice.
its now winding up the drive train, bad for it too.

drive, to dirt, sand, gavel or grass and shift out of 4wd.
or jack up 1 tire, and same,
one tire must be on slippery surface. at least.

http://www.rubicon-trail.com/4WD101/driveline-bind.html

this happens on all PT 4wd
or using LOCK on AWD. dont.

what wheel spins, double posted with this one add small fact.
front or rear.???? spins, gee, must i ask this?
you have open axles, right>? and this is normal
it is !
unless you use Lim.S.D. Axles (an option new)
or drag your brakes, creating a virtual Lim_S_D.
Limited slip differentials. (closed axles)
my 2008 wrangler does that, via software and uses ABS to lock a spinning wheel. (drag it)
but i cant drive on ice free pavement, are you, if yes, stop
PT 4wd is not for that. at all
you need full time,or AWD to do that magic.

got open axles? goggle that.

part time or awd ?
do no engage part time 4wd on dry pavement.!! only on ice or dirt.
do post what your tires are touching? dirt or pavement????????

if stuck in 4L , on dry pavement , pull over to side of road, dirt
then shift out. if no dirt anywhere? sand or gravel or grass.?
then jack up one wheel then deselect 4Low. back do 2WD
options for your car, (do post what you have)
qoute sales brochure:
Those going 4WD can enjoy the standard Command-Trac II, or opt for the Selec-Trac II, featuring full-time AWD, 4WD Lo and a rearward-biased torque split. (end quote)

how you drive both cars, varies greatly.
in your glove box is an operators guide , did you read that yet
under how to drive in 4wd or awd.??????????

sounds like the transfer case is broken.

a reluctant transfer case can sometimes be coaxed by shifting into reverse, backing up 10 feet, and then back to forward.

might be the vacuum switching valve on the front differential

there is a vacuum switch on top of the transfer case it applies vacuum when the truck is shifted in to 4 wheel drive . if you connect it to direct vacuum you front axle will be engaged all the time

go to car wash spray back wheels enough to remove dirt.

Try putting the car in neutral first. Try going in reverse while shifting out of 4wd.

This sounds like the linkage could have fallen or broken off. Have someone move the 4wd shifter while you look under the vehicle.