Rear A/C

The rear a/c is blowing hot/warm air in my 2000 Venture. Every once in awhile, it will turn cooler. The front a/c works just fine and even better since I just got a fan problem repaired. Any clue what it might be? I've got 3 small children and can't take them anywhere because it's 100+ outside these days.

it could be the blend door inside the rear panel [drivers side].is the rear a/c set to control from the front or rear?if set for rear control make sure the air temp is set to cold

This just happened to me on my Montana. Out of frustration (and an often used mechanics trick) I smacked the side panel in the rear of the van (drivers side next to the rear seat). The blend door promptly changed position and the kiddies now have nice cool air in the back. Give it a try, it might work. If that doesn't work you will have to pull the panel off and see what is keeping the blend door from moving.