i've been pluging away at my 4wd 2003 s10 because the front wheels aren't engaging when i press the 4hi/lo buttons. the l.e.ds in the buttons are solid (not flashing) and my transfer case seems to engage. i've checked the vaccum that is situated under the battery tray and works fine, i've checked the same cable that goes to the vaccum down to the transfer case and the vaccum line that seems to go to the back of the transmission. i've checked the electrical plug-in and seems to be corrosion free. the drive shaft turns all the way into the tranfer case (or at least it seems to) just nothing coming out of the front axle, only my rear wheels are turning. i tried turning the front wheels just with my hand and there is quite a bit of resistance. so i'm wondering if anyone has ever encoutered this problem in the past and maybe there's a fix/solution to this.
thank you
chris

 

If you have a book see if their is anyway to check the acctuator on the axle.