Here is a short list of the most common causes:
It doesn't really blow it out it just warms the cold air.
if its blowing, but not blowing cold its low on coolant. it takes r134a.
because you need to keep warm when it is winter and other times when it it cold
indoor air fan is not functioning. for that, there are many possibilities.
No, not if it's on a heat setting. Most home thermostats have a "Fan" setting that will blow cold air if the attic is cold.
Low refrigerant causing compressor not to start?
tad bit low on freon.
The blower motor could be shot, or a fuse could be bad. A wire could be disconnected.
1999 E320 air conditioner work on first and second speed, after 3rd blow warm air. AKINOHD@YAHOO.COM
Air conditioning will expel heat to the outside when cooling. On the heat cycle the reverse is evident
The a/c - heater controller is out...........
Check temperature control cable for binding.