Last summer the air conditioning worked fine in my 97 Grand Prix SE 3.8L model. I never used the A/C over the winter. Today was our first warm day and I turned the A/C on in the car and at first thought it wasn't working. I then determined that the A/C is blowing cold air out of the passenger side of the car but warm air out of the drivers side. It does not have dual climate control.

I figure it must be some kind of door or something stuck. Anybody ever have this problem and/or know how to fix it? Do you think it may come with time on its own?