Why is A/C blowing cold air and suddenly blows hot air, then cold again

The same thing is happening with our Kia Rondo. It started several months ago where the air would stop blowing cool but then it would come back on. Last month, it just went off completely. We took the car to have the air looked at and they replaced the relay switch and the freon. That seemed to do the trick. For about 3 hours when it went out again. Since then, we have replaced the relay switch AGAIN (they told us we might be blowing it out since I had been plugging in a fan) but that still has not helped. The air will blow hot one second and then cool the next. It is unpredictable. And annoying.

Go to a Kia specialist and get it diagnosed. The system is too complex for me to guess what's wrong without diagnosing it myself. If you want to find a Kia specialist, here's our directory link for you: https://repairpal.com/kia-repair-in-san-angelo-texas