Climate control failure

[colin cohen]

Leaving aside an electrical gremlin in the switching of your CC which is a
possibility, my guess is that your A/C has leaked its new 134 refrigerant
and has shut down because of low pressure. Conversions of older units are
notorious for this problem causing Audi to publish a Tech Bulletin on the
requirements for this conversion including the need for a change in Dryer
and seals etc.

SO I would take the car back to your A/C guy and have him run an A/C
pressure test, and if it has leaked, he should be able to track the leak as
most of the new compressor oils have fluorescent agents that show up with a
UV light.

Colin