A/C not working blows hot air

Well the first thing to check would be the fuses. There are two in the left dash panel fuse box, A/C fuse 1- 7.5A and A/C fuse2 - 10A, Plus check the 50 amp heater fuse in the fuse box under the hood on the left fender. If those are all good then the next thing to do is test the head unit. Do you have the automatic heater control unit or the manual one?

Such problems are caused by the air mix servomotor or its linkages. Try switching between heater and A/C a few times and note fif the servomotor is running correctly.

Yes, even the manual system has the servomotor.

Inspect servomotor operation.
1. Connect the positive (+) lead from the battery to terminal 4 and negative (-) lead to terminal 5, then check that the arm turns to "COLD" side smoothly.

2. Connect the positive (+) lead from the battery to terminal 5 and negative (-) lead to terminal 4, then check that the arm turns to "HOT" side smoothly. If operations are not as specified, replace the air mix servomotor.

You're welcome.

Have a nice day.

If just the air volume was low chances are the system is now seriously over-charged. Most systems on newer cars don't even hold two pounds of refrigerant, and two more, if you can even force it in, will likely destroy the compressor. When it's over-charged the liquid turns to vapor and gets cold too far down the line which means under the hood instead of inside the car. If any liquid sloshes into the compressor it will lock up at a minimum and potentially damage it.

There is no way to know how much refrigerant is in the system unless you recover all of it, then pump in a measured amount after drawing it into a vacuum. That's what your mechanic will do to assess the system's performance. If just the air volume is low, that has to do with the fan, a restriction, or mode door actuator not working.