Howdy, Stranger!   GMC Safari/Chevy Astro      • I had the same
problem. You are correct, this is caused by the vacuum lines in
the engine compartment. They are notorious for drying and
cracking. The line that is the likely culprit runs from the
driver's side valve cover to the front passenger side engine
compartment where it connects to a valve that contains several
vacuum lines. I would recommend replacing all your vacuum lines.
It's not really difficult to do, but it is easier to reach the
one at the back of the engine by taking off the engine cover
inside the van. The cost of the repair is about $2 if you do it
yourself. It's not very difficult to do and it will most
certainly fix your air conditioning problem.   • hav a 94 astro
van with no power to the igntion,windows,locks radio ,etc. but
do have head lights and interior lights ,battery is brand new
any suggestions where to start looking or part replacement   •
May be a late posting but the change or erratic positioning of
letters on the display on you