85 s10 blazer

i have a 85 s10 blazer that i have to manually hook up a vaccuum line to get the 4x4 to work...if i leave it hooked up it stays in 4x4..any idea's?

There has to be some sort of switch to turn the vacume on. I can't say for certian but I have an electric switch that't hooked into a vacume hose on my drivers side valve cover which might be it (I've got the same year) Try removing that hose the next time it doesn't shut off

ill try looking at that tomarrow...we got a foot of snow outside right now
tnx