97 Chevy Astro has Heater / Air Condtioning Vent Problem

So the heat and air conditioning in my 97 Chevy Astro van only comes out the defroster, and the bottom of the passenger side legroom area. Nothing really comes out the vents. I know what the answer to this question is already, I think. A broken vacuum line.

Where do I locate this vacuum line? Is this something that I can do myself? I am fairly handy with tools (I changed my own alternator, do periodic maintenence myself). Is there anything else that could be causing this?

Try this to solve the problem. The vacuum leak could be right under the hood ... check the vacuum canister attached to the underside of the hood. Look to see if a hose is hanging off it. Reattaching the hose should solve the problem. Hopefully this helps you.