A/C fault light is on....

[transit360]

These are '98 Bluebird QBRE shuttle buses. I had my "A/C fault
light come on after putting on a new coil and clutch assembly. The
clutch did engage for about 30 seconds, then stopped. Is there any
particular reason that anyone knows of that the "A/C fault" light is
on or how to diagnose the problem?
It's a Bock compressor on an 8.3 Cummins diesel pusher.

Also, does anyone know of any Bluebird or Cummins mechanics that
may know about these Q-buses? Maybe I could email them instead of
posting to a Wanderlodge group? Sorry, my options are limited and so
far this group has been very helpful even though I don't own a
Wanderlodge. Appreciate the advice.

Steve