Climate 91 PA

Hi Folks.
On my Buddy´s 91 PA doesn´t work the climate control. He filled up new refrigerant and the pressure´s ok, but after one minute on "AUTO" (cooling good) the system switches to "ECON".

Any suggestions?

What type of refrigerant did he use, R12 or 134a? Has anyone checked the high & low side pressure readings. If this was a conversion to 134a, did he change the expansion valve (orifice screen) accumulator, flush the system, add PAG 150 oil, & evacuate the system before charging?

Thx for the reply. He use 134a, pressure readings ok, PAG150 added, system flushed and evacuated. Maybe the expansion valve (orifice screen) accumulator wasn´t changed. I will ask...