I have a 2003 Stratus Sedan (4 cyl DOHC) with heat/AC problems.

I have changed the thermostat and reset the fuses per the Dodge service bulletin. After starting the car, everything seems to work properly. Heat blows hot. Switching between upper vents, lower vents, and defrost works properly. But as soon as you switch on the AC and turn the temp **** to cold, it's as if something gets stuck and the heat will no longer work. It will ONLY blow cold air thru the defrost vent. No matter how you adjust the *****, it only blows cold. This only occurs after you switch to cold AC. Am I dealing with a blend door/actuator problem? Thanks!

 

when it gets stuck will it work if you reset it ,could be a bad actuator ,first i would check the wiring to make sure everything is tight sounds like a communication problem with the body control module(controls blend ,mode and recirculating doors) and hvac controls

 

I had a similar problem on my 2001 stratus sedan after someone broke in and stole my stereo by forcibly pulling it out of the dash along with the trim. This left the climate control portion hanging out of the dash with the wires visible. The day of the theft I started getting cold air through the defrost vents instead of heat. At the same time I noticed(because it was night time) that the lights on the climate control section had went out. I started moving it around and then the lighting came back on and so did the heat. The minute I attempted to put it back into the dash the lights went out again and the heat changed to cold air through the defrost vent again. I started checking the wires in the back and noticed that the larger bundle apparently had some "wiggle" where it plugged into the climate control device. When I forced the connector to the extreme right the lights on the climate control system came back on and the heat stared working again. Ultimately I just put a shim in the socket area to force the connector to the right and I've had no problem since. So I'm guessing this is some kind of defect in the point of connection.