Either you are out of freon, your compressor is broken or your cabin filter is
plugged. There are other possibilities but these are the most obvious.
it's old and you need to change it.
Is the AC condenser in your system blowing cold air?
sounds like your freon may be low
needs heater core replaced wost likely be hind the glove box
Sounds like your cooling system termostate is stuck open.
if its blowing, but not blowing cold its low on coolant. it takes r134a.
There are a few reasons why a central air unit is not blowing cold air. The coils may be dirty, the unit may need freon, or the thermostat could be broken.
Replace Thermostat
when turning on air conditionor for cold air only get hot
What do you mean by "has no heat"? No air blowing out, blowing out cold air when heater is on, blowing nothing at all? Heater not turning on? What specifically is happening?
heater core plugged or air locked check to see if hoses going to heater core are hot
Just press the AC swith off and on - it shoud blowing cold air again. Do not know how or why, it works.