For a random period of time, there is no a/c (random, 15-30 mins or more.) Then abruptly there is fully cold a/c, not getting gradually colder! Sometimes when cold air starts suddenly possibly a whiff of refrigerant. The system seems to be fully charged when using a home a/c gauge. Any ideas? Thanks so much. This system had pretty much everything new about a year ago. Hyundai Santa Fe 2015.
I’d guess the blend door actuator is failing or the door itself is sticking.
Do you hear a faint click-click-click before the rush of cold air?
Another theory, the A/C compressor isn’t running when it should. A/C diagnosis and repair isn’t a very friendly diy’er job. Suggest to take your car to a well-recommended local A/C specialist. If they show you what exactly is broken, and no special A/C equipment needed, then you could decide to effect the repair yourself if you wanted.