I had both climate control ***** set on cold (all the way blue) and the fan control set at 3. Everything was fine for about 15 minutes, then the passenger side vents started blowing out hot air. I turned on the ac and cold air started to blow on the driver's side but hot air continued to blow on the passenger side. I moved the switches, (both climate control and fan speed, turning on and off ac), for about 10 minutes and the only way I could stop hot air from blowing out the passenger side vents was to turn the fan off. I continued driving and about 15 minutes later I set both climate control ***** on cold (all the way blue) and the fan control to 3 and it was fixed. I then moved the switches, (both climate control and fan speed, turning on and off ac), for about 10 minutes and it was still fixed. At no time did I turn off the car. Does anyone know what could have caused this?