I have a 97 Ram V8 360, 4x4 ext. cab. This morning I got in (very hot day) and the A/C decided not to work. Found that the compressor is working, freon is at a good pressure, the lines actually have condensation on them but there just isn't (or very very little) cold air coming out of the vents. The blower is working fine and is blowing air like normal or any setting, it just isn't cold. I played with all of the controls, hot to cold, cold to hot, changed which vents to send the air to, etc, that all worked. My dad had the problem of one of the doors slamming when hitting the gas so I stomped on it but nothing changed. Before coming to post this I hit the brakes and my foot hit the floor...darn brake line blew out. Luckily it was one up front so that one I can handle. I would appreciate any ideas on the air. I'd cr*p myself if the brakeline has anything to do with it. I was out driving prior to the line popping so don't think so.

 

Check the little servo motor under the dash, by the trans tunnel, on the right side, that is what controls the temp door. The little plastic couple tends to break, so the motor doesn't move the door properly.

 

IIRC, early models like a 97 just use a cable not a motor. But basically the same piece breaks that HeyYou stated.