Trouble with 4X4

First I want to say Hello to everyone...I new here
My first question is about the 4wd not working on my 96 Jimmy.
I 've looked at the vacuum actuator and it looks good but there is no vacuum through the hose...could the Vacuum Switch be causing this and if it's bad would removing the front drive shaft be the best way to get to it.
I get nothing when I put it 4-high and the rear diff locks in when I push 4-low...any help would be appreciated.

5 Days no replies...Great site you have here...Thanks for nothing...I won't be back....:nono:

We are sorry you feel that way.
Very few post go unanswed here.

If you still want help repost and give all information like what transfer case and someone will help you.
Also do some searching on 4W post here.
Here is a link that may help in the how to.
http://www.automotiveforums.com/vbulletin/showthread.php?t=572914
Good Luck