Air Conditioner on 1998 Ford F-150

The AC on my truck will work sometimes and then other times it blows out hot air. Is this a result of low freon, compressor, belts, relay, filter???

Asked by for the 1998 Ford F-150
my air conditioner goes from cold to hot
2 more answers , 2 more comments
I have a Ford F150 4.2l. When the compresser gets low of freon the clutch on the compressor will not enage thus causing the hot air. Based on My experience.
now that colder weather is approaching, I noticed that I don't have hot air either. Comments?
If you sometimes have cold air, and other times not. And then other times you can't get hot air, you may have a bad "blend air door actuator motor". Your ac/heat system has an electric controlled damper to blend hot air off of the heater core with cold air off of the evaporator core. When the air will get plenty hot turning the knob to red, but will never get cold - that's often low freon. When it won't get hot and won't get cold, and sometimes works better than others, that's often the blend air door actuator.
You wouldn't want to guess on any of those. You could begin to replace a part that's perfectly good, and still have a problem. You would save money in the long run having it diagnosed by a garage.
An A/C Diagnosis will be needed to determine the problem. It could be a few of the things you mention and it could be other things as well.