No, I *do* have an EPA Section 609 cert from MACS - not using someone else's license. Have you taken their certification test? If you did, you would know that it doesn't really teach you much about the actual service, just outlines some safety and environmental concerns and outlines some basics about refrigerant recovery and recycling. It doesn't teach you to be an AC tech.

Now, moving past my license/certification and my lack of knowledge in the field of automotive air conditioning...

What can be some of the things that might cause the AC system to not produce cool air, other than the lack of refrigerant?