Recently, my father - who is a certified HVAC engineer - retrofited my '72 Bonneville with R134a. The car, who's AC had not worked in YEARS, also received a new compressor, POA valve, expansion valve, etc.. However, the car does not blow cold.

Here are the symptoms:

The compressor comes on and stays on, but never cycles.
The fan speed is always high when the ac is turned on, no matter the setting. It works normally when on "vent."

My father is stymied and I am getting my butt scalded on dark green vinyl seats.

BTW, the very same retrofit procedure worked very well on my non-POA valve '82 Olds.

Should I - CAN I, go back to R12 - or is there anything else I can do?

Thanks, guys.

Jayson
Nashville, TN