97 grnd chrkee,
so i'm getting air only through the top ducts, i took the control panel out and all the vacuum line are on.
is there a main line i should look for as the chilton book gives me no clue and would like to get fixed before i sell it.

Look under the hood for a vacuum line off. The default position for the heater doors is the defrost position when there is no vacuum signal to the controls.

The hose goes thru the fire wall about halfway over on the passenger side. follow it to the engine and see if it is disconected.

JD