GMC Repair: air conditioning auto, pressure ratio, freon

Question
I have a 2000 GMC and would like to know if there is a rule on want the psi should be for one pound of freon. I put guages on my air and get different readings thank you very much Jim

Answer
No there is no freon weight to pressure ratio.

The way it works is that freon has a direct temperature to pressure relativity, i.e, 60 degrees F = 60 psi. So what you should look for with guages on is about 30-35psi on the low side and up to 350psi on the high side while running. The high side pressure will change with the ambient temperature change.

Why do you ask? Is your A/C not cooling?