Having had the dash A/C completely redone we haven’t used it since. Today I fired that up and found the A/C - Heat - Defrost mode switch made no difference. It was stuck in defrost mode so no A/C. Thanks to Steve’s forum and a long talk with Bill Lampkin I started looking at the Vacuum pump and resevoire which looks like a softball and is in the generator compartment on the firewall. A vacuum line had become dislodged and problem solved.
Hope this helps someone!
