I notice when i set the AC controls to the "Economy Vent" setting, only the dash vents will blow out, and i notice if i stomp on the gas then the dash ones will open up and start working. i remember my 1988 caprice used to do this as well. it only does it on the economy setting.

I notice when i set the AC controls to the "Economy Vent" setting, only the dash vents will blow out, and i notice if i stomp on the gas then the dash ones will open up and start working. i remember my 1988 caprice used to do this as well. it only does it on the economy setting.

My caprice is the same year as yours and i have similar problems. Although, the dash vents engage, they do so very slowly. And there is a very noticable hissing noise coming from the dash. I took the cover off and foudn this black plastic wheel that would rotate when you change the vent setting "towards the right of the AC module". Somehow when i moved teh lever, the black wheel would come out of place, but when i sort of pushed it forwards so it was flat in its place again, the hissing would go away and the air from the vents would start to come out much faster. I dont know if there is some kind of retainer cap that is missing but thats what it seems to be. I have a video posted on youtube that might better explain this. http://www.youtube.com/watch?v=4PC9PtYytCQ

I had that issue right when i bought my 83, that little black wheel was the first thing i replaced and it fixed the hissing noise, i think the problem im having now is beyond that little black wheel though. when i had my other caprice someone told me it was the vacuum pump

I had that issue right when i bought my 83, that little black wheel was the first thing i replaced and it fixed the hissing noise, i think the problem im having now is beyond that little black wheel though. when i had my other caprice someone told me it was the vacuum pump


under the hood is a vacuum ball soft ball sized going to it is a vacuum line and a check valve to trap vacuum in this ball.... the trapped vacuum goes to a/c controller under dash... when engine is off this ball should hold vacuum if not find leak.........

ok i know what that is