Good evening. I have an AC question

The 2 vents on the drivers side have warm air blowing out. ... But a system that is 1/2 pound low will cause the passenger side vents to blow cool or cold air, and the drivers side to be less cool or even warm on this car. There is simply not enough freon capacity in the system to cool the air to the drivers side.
https://www.justautorepair.com/buick/century/cool-passenger-warm-driver

http://ricksfreeautorepairadvice.com/car-ac-blows-cold-blows-warm/
Car AC blows cold then blows warm Ricks Free Auto Repair Advice

Is the radiator fan still coming on ? Is the compressor running ?

If you turn on your AC on one day and nothing happens, you may be dealing with a major component failure. Your vehicle's AC system consists of a compressor, condenser, evaporator, expansion valve, a series of tubes and several fans/blowers. If either one of these components fails to do their job, it may result an entire system failure. For example, if the evaporator blower motor burns out, you will get little to no airflow through the vents.
Most modern vehicles also have safety mechanisms that may prevent a component from engaging if the pressure is low in the system due to a refrigerant leak. Refrigerant can leak for many reasons, including undone welds, loose connections, corrosion, physical damage from road debris, etc. Look for oily stains underneath your car, as they may indicate a leak. If you suspect a refrigerant leak, take your car to General Automotive. We will test the pressure and use special dyes to pinpoint the leak.
Warm Air is Coming Out Instead of Cold As you get in your car and turn on your AC, you probably expect it to be blowing hot air for the first minute or two until the system cycles through enough to cool it. But what if the air never gets cold ? Or maybe it it gets cooler, but not cold enough ? No, your car didn't get confused and turned on heat by accident. There is likely a problem with your condenser.
A condenser's job in a vehicle is to cool the warm refrigerant that was used to make the air cold in the evaporator. A condenser has coils and a fan to push the air through the coils and thus cool the refrigerant. If the condenser coils get dirty or clogged, or if the fan fails, the refrigerant won't be cooled completely, so the air will come out warm. It's best to take your vehicle to an experienced AC Repair professional to troubleshoot this problem if you don't know your way around under the hood.
Cold Air Blows Intermittently So you went for a road trip or a long drive, and after 30 minutes of driving realized that your AC suddenly stopped working or switched to blowing warm air. The cold air returns shortly, and the cycle repeats itself for as long as you are driving. What's wrong with your car?
Intermittent cooling is often caused by the components of your vehicle's AC system freezing up. Typically an iced over evaporator is the culprit. An evaporator covered in ice can't cool the air, so you would have to wait until the ice melts, which is why the cold air eventually returns. There may be numerous issues causing the icing-from a dirty cabin air filter to a blocked evaporator drain or an overcharged system. Look for puddles of water under your car-this could be a sign of a freezing problem.

What do you mean when you say it wont shut off? is it blowing hot air or do you just feel a lite flow of hot air even if you have the settings to cold?

If this is the problem that you always feel hot air at low flow and the ac goes to hot air then i would say one of two things, first if you have the selector to cold and you feel hot air then there may be a problem with the blend door, this door move to allow hot or cold air, the door may be broken or just a bad motor that controls it. keep in mind if the ac system shuts down for any reason the air then will be warm, it will be about the same temp as outside and maybe a little hotter.

this problem almost sounds like the ac compressor shuts off and then you are getting the outside air which is hot, there are many reasons for the compressor to shut off, it could be the compressor clutch heating up and disengaging , this would be due to a bad compressor clutch.

another reason is the fans are not working, the best thing to do is when the system starts to blow warm check and see if the compressor is running, start engine and look at the front of compressor, with ac off the front of it will not move, and then with ac on the front will spin, check it out and let me know, if it blows warm air and ac is not working then it may be compressor problem but if you are getting warm air and the compressor is spinning then it may be a door problem.

This is hard to check with out testing the system, so i listed a few things to check and let me know the out come. also the ac blows cold for how long before it gets hot air blowing out of the vents, good day.

It may be getting low on freon sometimes they leak out

Check the magnetic clutch is engaged on front of a/c pump, have the motor running, a/c on and fan on high, if the centre hub is static the pump in not switched on, this can happen when the gas pressure gets low.

you should go to a mechanic and check the A/C if the freon id low it won't cool , some time at mornig it give you the semsation that is cooling but probably not..

if it is the same thing that is wrong with my frontier. check to see if the compressor is turning on when you use the ac. if not you might have a bad connection that is intermittantly preventing the compressor from getting the signal to turn on. get a service manual and a voltmeter and you can fix.

Control panel going bad.