4x4 not working

I have a 93 Jimmy and am having 4x4 problems. Sometimes like now, when I push the button to go itno 4hi it does nothing and the same if I push it to go into 4low, the buttons don't light up, no sounds nothing. Other times I can hit the button the light comes on like usual and can even if quiet enough hear it engage. I'm thinking the switch needs to be changed but not sure? Looking for some help here cause we're getting dumped on with snow and don't really want to be without 4x4 when I need it.

This forum is way to slow.

It's either one of 2 things.. It's either the vac switch on the side of the transfer case, or the encoder motor...I would lean more towards the encoder motor.

encoder motor...where is it located and is it tough to change...can I use a salvage yard parts...?
I was on the lake ice fishing and got stuck in 10-12" inches of snow...light blinks and becomes solid...but, doesnot go into 4WD???

Just for reference I just got done fixing this problem on my 1994 Jimmy, I have made a website since it seems alot of people have this problem. but this is how I fixed mine, may or may nto work for you but there are pictures etc to help you along.:

http://myrepairs.50megs.com/