Blows hot air then back to cold
Turn on air conditioning blows hard cold air and after a few minutes blows hot air then back to cold after awhile.
This may be from the air conditioning system being low on Freon. You can listen for the compressor to cycle on and off. When the Freon gets lower than normal the compressor tends to cycle on and off more frequent. If this is the case, a top off may be in order.