just bought 94 ford conversion van. 24,000 miles garage kept etc,etc. just drove it for 1st time. seems when under any type pull the a/c drops from in dash vents to under dash as near as i can tell. it doesnt seem to cut off. just seems to start blowing under dash im pretty certain. called p.o. who told me ford said that was they way they work.has done this since new and he did have it checked. im not sure thats correct though. are you? im thinking vacumn problem possibly. any help? thanks so much.