I am new and need help please. A few weeks ago my 2013 explorer had great air conditioning. Then it started blowing out hot air instead. My mechanic was going to add freon but it was full. So, I figured I would wait to fix it until I had some money. Then I took it to get the oil change done. When I got back in my car the ac was blowing cold again. It worked blowing cold instead of hot air for about two weeks. Then I set up a DVD player for a client to watch in the car. About 20 minuets into the movie the front screen blinked a couple times and the air was blowing warm again. I took it to a dealership and they said it was the condenser. My son who lives in another state and was a mechanic in the army said "no way" he said the condensers don't go in and out like that. Has anyone else had this problem and if so what was the problem?