Problem with AC unit blowing superheated air wwhile on AC

  • 23,500 MILES
Ac settings on cold and will sometimes run normally but with an intermittent disruption but is now doing a continuous blowing of superheated air from the 3 vents and cold from drive side vent near door only. The engine temp is normal the radiator fluid is normal and the settings on the ac have not been altered and are set on high cool ac. There appears to be no other problem with this car. Could there be a fuse or some type of relay that needs to be checked and if so which one. I have a helicopter mechanic at my disposal but I know I will have to take it in if it is anything serious and I believe it is. I would appreciate any information. Car just went out of warranty last month. THanks Theresa
Do you
have the same problem?
Friday, November 11th, 2011 AT 12:09 AM

1 Reply

There are ea few things that can cause issues in modern automatic A/C Heater systems.

To start, you should always have the trouble codes pulled on modern cars before beginning a diagnostic of an unknown problem source. Advance auto and Auto Zone both do it for free and it can help eliminate or solve the issue.

The pressure of the refrigerant is extremely sensitive. A few tenths of a pound off and the A/C becomes a heater. I realize you have not had your A/C serviced, more than likely, but it not out of the question. However, you do have other issues, so there could be a different core problem causing a series of problems. I have seen the, "Superheated Air" happened and if it was really hot, you should have the refrigerant pressure checked.

Next, I found a bunch of diagrams I am going to give you with the vent system and a separate diagram, unfortunately I have to do a screen capture to get charts when they are separate, to give parts description of each component. They are called the Vent System and the "Duct System Parts Description". I thought of putting this information in this dialogue, but I thought it might get just as confusing as the diagrams are the first two and will be easy to correlate rather than going through all this text.

The fresh air system lets in the air in a few interesting areas, the side most vents and the vents under the seats. It does pass through the system first as you will read in the provided air flow description, including going through both the Evaporator, which cools air and the Heater Core, which heats air.

Then you will find information on the mode control, actuators and the direction of air inside the system. This is where these types of problems usually are found like you describe.
There are vacuum controlled mode door controls, which simply route air. And then there are mode control actuators that electrically actuate and control the temperature by the amount they are opened, and switch between one side of the car having a different temperature than the other. If your car is so equipped, I believe this actuator is faulty. I would be the actuator for temperature control of a set of doors that keep each side at different settings. There is another part that also has a job in setting this when using the heater. There is a Coolant Circulation Valve, part #6 in parts list, that separately controls coolant flow for both left and right sides.
With the combination of issues you have and the current status,

I believe this a top of the list candidate for the issue causing the problem.

It gets so complicated that I might not have diagrams and descriptions good enough to help you locate them, if you intend to replace them, without having exact information, this job could go bad quickly as it is such a complicated system. Diagrams and the such don't always translate what you will really deal with when you get into the system. Changing out this actuator, if that is the faulty part, is going to be a tough and tedious job that has to be put back together exactingly or you may have worse issue than when you started.

The system is so, "compartmentalized, it looks like you could remove it as an entire, "Box" and either fix it or replace it, but outside of the car because working under the dash on this looks near impossible.

Start with the code pulling, then get back to us with any questions. I would try to find a reputable repair shop that is familiar with the car or you will spend a fortune at a dealership. This site has links in to to help you locate reputable repair shops near you if you just use the search engine with anything about repair of Chrysler repair. It provides them with ones in your area and shows how far they are from you in some cases and gives reviews.

I will get back to you ASAP as soon as I see a response from you.
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Friday, November 11th, 2011 AT 3:05 AM

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