had/ having a similar problem. At first my 4x4 and AC vents didn't work, then I found a white vacuum line going from vacuum pump area to the 4x4 vacuum switch on top of the transfer case was clogged, simply unclogged it and 4x4 works now. still have ac vent issue. hope you get 4x4 working. it comes in handy.

 

Well guys I followed the vacuum lines as much as I could and I didn't find a bad spot... but the actuator on the axle is really bad looking so I think I'm going to replace it and see if that'll do it

 

my brother has a 96 having heater problems he found a vacuum leak on the little black line just behind the turbo the vacuum line was rubbing on a metal line and put a hole in the vacuum line about 8 inches before it goes into the fire wall