Ac leaks are hard to find. there is a chemical that can be added to the Freon. Under a special light it will show up. If it is a small leak it may not show up, especially if its on the compressor behind the clutch.
You may have a leak in the system, check that out.
You have a leak somewhere in the ac system. A dye can be injected into the system and with the use of a black light and special glasses the leak can be detected so repairs can be made.
you have an AC leak
$400 to $600 depending if it has ac or not.
Blown fuse? Refrigerant leak?
You may need to recharge the cooling chemical in your unit.
in the low side hose by the condenser
Under the hood, on the passenger side firewall.
The relay on the passenger side firewall is the ac compressor relay.
http://www.swampy.net/iceuse.html
AC System probably needs refrigerant added.
It is located under the AC and Heat instrument panel