Ok I have just purchased a 1991 Blazer about a month ago and I was driving up a hill in fourwheel in the snow and it just popped out of four wheen, the shifter is on the floor and it didn't move or anything it just came out of four wheel drive. I have checked the fuses and the vaccum lines and they are good. If anyone has any ideas of what my problem is please let me know

 

Welcome to the forum.
It would be easier to help if you gave us some vehicle info,

 

its a 1991 blazer with the 4.3 I don't know the tranny or the transfer case