my 1995 S10 Blazer which I am having plenty of problems with (eairler post ). what about when air will not come thru the vents, but on the floor or the defroster vent. I've been checking for leaks but found none !! HELP!!!!!!! in south Alabama

 

If it will come out of the floor and defrost vents, but not the front panel vents, then you've either got a leaking vacuum line in the dash, or your control head has a problem somewhere inside it.

I don't have any schematics for the earlier gen, only for my '00 and like years... Sorry.

 

A leaking vacuum line could be anywhere. Start by finding the vacuum lines on the passengers side of the intake manifold/trottle body unit and between the distriburator cap area. Look for some rubber hoses. Follow them everywhere. They should go to a ball, to the t-case, to the vacuum disconnect under the battery, and to the inside of the truck to control your vent settings. Depending on the year of your truck it is also tied into the timing of the engine via the distriburator. The hose likes to leak/break at a connector. If your hands turn black from touching the hose, replace it, all of it. If the hose is cracked, replace it, all of it. Most autoparts stores sell it by the foot. Get more then you think you will need, its cheaper then running back to the store for more.