2000 town and country,,, heat gage is stuck on H, we just had a air sencor replaced. So we know its not that. But we think its just a simple part switch chip or part in engine.

If you checked properly and coolant/rad isn't getting hot, coolant is up to proper level, then I'd replace thermostat.

probly camchaft sensor

Regular prestone will do the trick

If it happened suddenly, it is probably the blend door actuator.

Please see my tip at http://www.fixya.com/cars/r6235876-no_heat_fan_blowing_cold_air . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.

Your blend door actuator is above the accelerator pedal. See picture below.

most of the time the resistor is located downwind of the blower motor so it should be not to fao from the blower motor in the right rear of the van behind the quater trim panel which is the hvac unit is located

I dont think it does, just call the parts store and have them look one up, if they dont show one, then it doesnt have one.

Sure the AC is working? If so, the suction line to the compressor should be nice and cold to the touch and sweating. If that checks out, and the fan is working, then the issue has to be with the device/switch that directs the cold air from the evaporator to your dash vents. That could be a PIA because it might just be inside the dashboard.

have you calibrated the unit a chrysler tech could tell you how over the phone it is simple mut my info is on my box at work

u will need to repair the passenger side air temp control blend door, either the door is stuck or the small electric actuator that moves it is defective.

thermostat stuck open ...good luck