91 corsica, 87k miles, auto...converted a/c to 134. worked great for a few months. Now blows un-cooled air. Compressor still activates, output side of condensor is cold, dryer input remains warm. I'm thinking that the expansion valve is not opening at all, or the orifice tube has clogged.

Questions:

1. What do you think?
2. Where is the expansion valve?
3. Is there an orifice tube?...if yes, where?

:D