I have a 1994 buick century. The a/c will work one day but not the next.When it works it blows cold. It may work for 15 min. then start blowing warm air only to start working again 15 min later. All of this during one trip the car is not turned off.
That sounds like it may be freezing up. Are you running it on re-cycle? It may need the refrigerant pressure checked. (NOTE: the refrigerant charge is a specific number for your application. Too little is bad, but too much is also. A properly functioning A/C does not use refrigerant so if it requires fresh refrigerant, then there is a problem that should be address. A band aid might have covered over that little spot on my leg, but since it was cancer, covering it up was not enough. I have been cancer free for over five years now. Not bad for someone who was given a 20% chance to live five years 40 years ago.