A/c debacle

I have a 2003 grand prix 3.1 engine. The ac worked perfect last year.suddenly this year it is not blowing cold at all. I got a can of freon and put it in. I am now getting cold air out of the passenger side vents.well so it's half fixed lol. I still have two issues. One is the compressor is running constantly and will not cycle and the other isne drivers side will not blow cold. It has dual climate control.it will turn all the way to heat but only cools to about outside air temp. We had a Buick long ago that did something like this and we had to manually flip a door under clove box to get heat or ac whichever we wanted. Does this sound about the same.mi only have a low side pressure gauge for the a/c. It shows 60 until I turn on ac then when ac is kicked on the gauge drops to 30 and stays there. Anyone have any ideas. This is driving me crazy. Thank you all

OK, since you had no cooling until you added freon, then obviously, you have a leak......the compressor you have is a VDOT....it is not suppose to cycle....it runs constantly when commanded on.....it does this by varying the stroke of the compressor, depending on the load.....

So you have two possibilities.......you are still low on freon, or the temp do0r on the driver's side is not closing all the way....

You can check the temp doors this way.......get the vehicle to normal operating temp....have the dual system off....have the A/C off and in vent mode.....command temp to full hot and measure both sides with a thermometer....should read 145-155F......then adjust to full cold......should measure close to ambient temp of outside air, but 5-10 degress warmer due to the hot engine compartment.....but both should be the same....if the driver's side, is much warmer, you have a temp door problem....

If both sides read the same on full cold, with the A/C off, then you need more freon....what happens is, if there is not enough freon, it tends to short circuit through the upper half of the evaporator....the lower half has less freon going through it and cools the air less....

There is only one way to add the proper amount of freon....you fix the leak....you evacuate the system....then you add freon by weight....

You need the correct amount of refrigerant to cool both sides- your leak is must likely the compressor belly o-rings....

Ty for the response. I had done some research late last night and found something similar. What i would give for an ac machine. i guess ill have to make him an appt at the local shop. Im just hoping tye leak isnt something big. I know when i was hooking up my guage the low pressure valve was leaking a little until i worked it a couple of times then it quit. I keep telling him if he keeps getting cars with all the hells and whistles hes going to have to learn to fix it himself lol. Ty again for your time. I will have him try thr blend door test and see if that is the issue. I know that it does go to full heat so hopefully its just a lack of freon issue. Ty again and have a great day