1991 S-10 Blazer vent problem

My blazers defrost, ac, vent, and everything else used to work ok. It used to take a couple minutes after I started my car to start working and now none of it works. Maybe a bad relay or something? Thanks in advance.

id say you have a vacuum leak somewhere.

which in turn could be why your 4wd doesnt work either. however im not positive that your 4wd system uses vacuum. i cant remember how the floor mounted lever system actuates.

The '91 with floor mount uses the vacuum actuator under the battery box.

I posted under the 4WD before reading this as to what to check but in light of this, Cobra1 is right, check your vacuum first.

Thanks a bunch guys, Ill do this and let ya know what happens