2002 Caravan...we were riding in the van two weeks ago coming home from San Antonio. Stopped at walmart and when coming back to the van, noticed a huge amount of water under the van. Seemed more than normal from running an ac. Coming home from San Antonio, we had the ac on high, but noticed it wasn't putting air out with enough force. Barely felt the cold air coming out of the vents. Next day, ac ran fine. Fast forward to last night...we drove the van to the next town to shop and had the ac on high..blowing really good...but it went from COLD air coming out to just regular air coming out...as if we switched it to "vent" air. It stayed like that for about 10 min, then the cold air came back...lasted for several minutes, then back to regular air again. Same thing this morning going to a little league game...but the regular air is lasting longer than the cold air now. Had to roll the windows down and turn it off. Blower sounds good and all blower settings from Lo to Hi work fine. Just intermittent cold air that seems to be getting more sparse. Any ideas??

 

It sounds as though the evaporator is freezing up. Was the huge amount of water you saw near the front of the van or near the back? I'm assuming the front. If the evap freezes up in will inhibit air flow through it and the vents wont blow well until it thaws. The AC system is supposed to cycle off or limit the flow of freon (depending on the system) to prevent this. It almost sounds like it could be an overcharged condition, too. Was it serviced recently?

Take it to an AC shop unless you can troubleshoot the system yourself. Good luck