I am still having trouble with my 4wd. I found a rubber line 7/32 that comes out above the brake booster on my 95 blazer. The other end is attached to the black plastic ball that is mounted to the underside of my hood. The problem is I don't know where this is suppose to attach to. It heads toward the back of the engine. Can anyone help me with this? thanx. wnk.

 

It probably heads towards a plastic vacuum tee on the passenger side of the transfer case.
There is a vacuum switch on the upper right side of the transfer case that is fed by that vacuum hose....I believe.

 

This line does not have any vacuum when I start the vehicle. I am assuming that it must plug into some sort of vacuum source?

 

I do not know exactly what you are driving ....but on my 96 if you follow the hose from the PCV to it's source, the source for the hose you are talking about is directly below it.