Air conditioner blowing hot air on 2002 monte carlo and it has freon in it

you dont check if blowing hot air you need service

Have freon level topped off and checked for leaks.

If your car is more than a few years old, it probably has a leak or a worn compressor. You can add too much freon for the system. It needs to be vacuumed down to a negative pressure before adding freon, and then checked for compressor function and leaks. You may need to take it in to a reputable shop.

This problem is usually due to bad compressor. They adjust the temp of A/C by the outside temp.

Well ac r very hard diagnose the cheap way is to buy a can of freon with dye or leak detector turn on car and ac system at full blast open hood u should have to connections one with redtop one withblacktop u connect to black top make sure you shake can well the can should get cold and see what u get if it gets cold see for how long if gets hot after a couple of days you most likely have a leak. Expensive way take somewhere have them check it to check they will probaly charge anywhere from 25 to 75 to check but not fix they just will tell you what's wrong and how much it will cost shop around! They charge so much because they have to hook it up to a machine.

a leak

Take it to a garage and have them evacuate the system and refill with refrigerant. you have air and non condensibles in the refrigerant system.

always charge too the large port .it may have a blue cap on it.

Try a new thermostat

It's probably an r-12 unit. If you don't have a license to handle freon, you'll have to take it to a shop. It will need to be totally purged, vacuumchecked & refilled.