I have a 2001 Grand Prix, 3100 engine. Today was the first time i needed A/C and nothing. It worked last summer. It has dual climate control and I noticed that the passenger side air is cooler than the driver side. Now let me iterate that the air is not cool but warm, there is just a slight temperature differance between both sides. When I change the temp. from cold to hot I do hear the change as in the "blend door" is operating and the temp. goes to hot. Any Ideas? Thanks Pablo