My 89 Aerostar has suddenly stopped blowing air through anywhere except the screen vents. The A/C still works fine it is just that cooling the windscreen is not a priority! Any ideas? Clive

do any of the control options such as floor or vent work at all? or is a flap stuck on defrost?

sorry to here about that. I had the same problem. Your older aero has alot of vacuum lines. Undo your dash just enough to pull the functioning controll module with your switches away from your dash and look at it. You have either gotten a broken hose (about 1/16th inch diameter) or it simply disconnected itself from one of the small nipples that the plastic tubing connects to. If you are a beginner at this as I once was hear is a very simply approach that you can take. As you put it the cold air only comes out of the defrost--Is this correct? Okay then, start your van, put the air on and look?

Regarding the ventilation only coming out the windscreen/defrost, also check the vaccum lines under the hood, high up on the right side (driver's perspective). I had a crack in one where it bends around into that cylindrical vaccum reservoir thing. I patched it with an inch of fish tank tubing and a hint of silicone glue until I get around to buying new lines. Mike California '91 XLT 3.0 5-speed 97K miles and running good, but only on $2.60/gallon premium gas! 20+ mpg fuel, 750 mpq oil(!)