95 3.8 a/c problem

What would cause the a/c to only blow out the defrost vents?

I have the same car and just fixed the same problem. The switch that directs airflow in your heat a/c system uses vacuum. If you look under the hood on the driver side right near the firewall there is a vacuum distribution block there. One is marked a/c(third one down). Check to see if the line is cracked mine was. if not right there then trace that vacuum line till you find the leak.

Thanks for the help. I actually checked that very thing that day and the vacuum line was cracked and broken in two different spots. Thanks again.