When I turn on the air conditioning it sounds like I have a vacuum leak and the air only comes out of the heat vents. Do you think it's a vacuum leak, a stuck blend door, or something else?
some of these older vehicles had vacuum dash pots that are mini diaphragms that pull open the doors under the dash when operated and then a spring pulls the door back when cut off. there are small hoses running from the vacuum switch to these diaphragms. that's the fun of owning a vet. you get to stand on your head to work on it.
