well here's the prob ..on my 87dl....all of my heat is directed to the bilev button...

this is what is does;

defrost....no heat or air

heat........no heat or air

Bilev ........all air/heat

vent....ok

any body have any ideas . is this fixable by just taking the top part of the dash off.:?

spark...............

This most likely is a vacuum hose problem. Check all the vac hose connections, specifically the one's connected in the vicinity of the cannister inside the engine compartment on the passenger side.

ok thanks

There's a vacuum connector near the accelerator pedal that sometimes comes undone.