Hi

I have a 2000 g caravan with a 3.8 and I am getting a light mist from the centre dash vents when the a/c is going full blast, when I turn down the temp setting a little it stops. It smells like stale water but it still blows cold air. by the way is there a cabin air filter in this van, I know the gm's do but I haven't been able to find it in this one. any help on this would be greatly appreciated.

It means the pressure is low in the air conditioner system.

I would check that the drain tube is not plugged up. The evaporator under the dash gets full of moisture from the condensation from the a/c , especially on humid days. There is a drain tube to let the water run out under the van. If the tube is blocked, the water will build up and spray out the vent that is close to it, the center vent, or it will also leak down on your carpet under the dash.