it might be the air condition gas or most probably the air condition compressor
If the system has a full charge then the thermister is most likely the cause for it not working.
There is a bad or damaged ground to the the ECM
a leak
A fan in the system.
Start with the lack of freon.
Check the fuses.
from seeing your ugly face
It would greatly help to know what engine you have and if it has air conditioning (working or not)
It could only be either a fuse, the switch/or wiring, or the motor burned up. I would check the fuse 1st.
Most likely, your air conditioning compressor is cooked or its pulley clutch has seized. Hopefully it was the pulley, because the compressor is not cheap.
No because it would cause attention
Installed the battery backward. A short. Or a fuse blew.