That's not the right answer. you still have a problem. That is just the "recirculate" button so that the blower just keeps moving the air around that's already in the van. The other button is the fresh air button. It pulls in fresh air from the outside. The heat or AC should function just fine on either setting - yet if our AC is not cooling well (e.g. from low refrigerant) it will cool better on recirc. Either way - you have not solved your problem.
What happens when you put it back to where it was (fresh air)? Is it still cold, or does it get warm on one side again? Thing is, you may have found a 'solution' to your situation, but it is only temporary if the problem comes back when the HVAC system is in a normal operation mode (recirculation mode isn't really a normal operation but it helps during long trips to save gas mileage when using the A/C...when you have only a passenger or two. More than that, you want to use fresh air setting. Trust me).
Not saying that your vehicle has a problem, but just save up a little and have the "issue" looked at soon. Will probably save you headaches later on. -- Windows 7 64 Professional|AMD FX 8150|Asus Crosshair Formula V Motherboard|8GB G.Skill Sniper Series 1866 DDR3 RAM|EVGA GTX560 Ti (Fermi) DS SuperClocked x2|Corsair CMPSU 850HX 850w Modular|Lian Li Lancool PC-K62 Case