I have a 2010 Ford Fusion se 4 cyl. It has been a great car and have had very minimal problems out of it but recently as we reached 245k miles the A/C has been acting weird. It will be on and cooling one minute then you'll hear the vents change in sound and hot air will then blow just like if I had switched it to heat. This is not warm air here, this is full blown heat! It's very frustrating and I have no idea what it could be and I've got a wife and two girls to keep cool so the pressure is on your help would be greatly appreciated!