No Four Wheel?

i have an 88' s10 blazer, with a 4.3 automatic in it, 4x4, but there is no fourwheel drive in it now, it was working after you put it in fourwheel it took a couple of mins then finally sliped/kicked in? duno now it won't go in, the shaft from the transfer case is spining but the hubs or something won't engage????? Need some advice on this since i live in the middle of no where an four wheel drive is a nicesity.

I had an 89 blazer but recently sold it.Great vechile. I also had the same problem The 4x4 is really simple. When you put it in 4x4, vaccum is placed on a cable that it attached to the 4x4 transfer case. The cable starts under the battery and ends on the tranfer case. 3 things to check. 1. Check the diafram under your battery, make sure it is working (no holes etc). 2. On either end of the cable is a little wire that holds on to the cable. After a while this gets broken. You can go buy new clips for little of nothing or you can make your own. Not a big deal. (This happened to be what was wrong with mine). Lastly, their was a vaccum switch on the tranfer case that i had to replace. Sorry, but if forgot what it really was. I just remember that it screwed into the case and has 3 lines coming out of it.
I hope some of this info. works