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 derost 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. Now I'm being told that I need to get my climate controls replaced because the vents are not opening up. Before I buy could this really be the problem.
Find where the heater hoses actually pass into the car. They are usually found going into the car behind the engine at the firewall. There should be two black rubber hoses, about 5/8" diameter. With the engine running at operating temperature and the heater on, both hoses should feel pretty hot. If one hose is hot and the other feels cold or lukewarm, the heater core is most likely plugged.
This will tell you if heater core is working right. Then if good it has to be in HVAC controls. The temp blend door is first suspect. By locating and watching if it operates while dialing heat will tell you if controls or actuator itself is at fault. See pic.
January, 5, 2012 AT 1:13 AM
Had the Climate controls changed and checked the heater door blend actuator which was fine but the heat still only come out of one vent and only when its on the control that pulls the air in from the outside. Also checked the fuses which were fine. What could be wrong with my car?