i bought an r134a recharge kit and I was testing the pressure before adding any refrigerant and the guage read 150 psi, way over what it should be reading. What does this mean and how do I release the pressure?

The a/c is not cool at all, on the highest settings it just blows warm air out.

 

r u sure u have the valves open when the guage lines connect to the A/C lines? if u did have them open and had that pressure,the orfice (sp?) could be clogged i think.

when was the last time the A/C did work?

 

it was working fine about 3 days ago and i didn't open the valve on the can because i didn't want to add pressure to the system if it was already reading 150 psi

 

if you have not added any freon since the system was working and it is reading 150 psi then there is a problem. The system will not operate at that high of a pressure. Like rice killer said, the orfice tube could be clogged, if it is and you keep running the ac the comprssor will probably burn out as well because after a while it is not going to be getting any oil. you may need to have someone who knows take a peek at it, a/c can be tricky sometimes.