I am having a problem with my heat. Checked everything out, no leaks, no overheating, got a new thermostat and bled the valve for air bubbles. No foggy windows unless its too cold or raining when I turn on the defrost it defrosts but with cold air. Only one of my vents gets warm not hot and thats the one on the drivers side. The 2 in the middle go from warm to cold every time I have something done to get it fixed and the one on the passenger side is freezing all the time no matter what. The last time I tried to get this fixed the guy went in the car on the floor behind the controls and opened the vent, the 2 vents in the middle began to get warm again but eventually went back to cold after driving 10 min. The vent on the end was cold. Had the Climate controls changed and checked the heater door blend actuator which was fine but the heat still only comes out of one vent and only when its on the control that pulls the air in from the outside. I also had checked the fuses which were fine. What could be wrong with my car?