If the compressor is not turning on it could be as simple as low refrigerant level. If the compressor IS turning on, it might be a stuck heater core valve.
TRY TO UNHOOK HOSE FROM WASHER AND BLOW AIR THROUGH
if you run it very long you will blow the seals
The head gasket is about to blow.....Typical ford..
Low refrigerant causing compressor not to start?
== ==
Check the Horn wiring and if this is good then replace the horn.
Plugged PCV valve or hose
First check to see if there is freon in the system and if yes then check the pressure switch and pigtail........
This is the starter fuse I am talking about. It doesn't blow every time. It might go weeks before it blows again.
no heat ford f 150 4.6 no heat ford f 150 4.6 Check the coolant level in the radiator first (NEVER OPEN HOT) most of the time it 's the coolant level being low that causes the heater to not blow hot...
The thermo-stat may need changed or you may need a lower pressure radiator cap - Make sure you keep an eye on you could blow the head gasket -- also you should check your oil to make sure that water isn't in the oil .
you could have a short in your wiring, or your fuel pump might need to be replaced(short, damaged, draws too much power)