Over the past few months, I've been having an issue where I would have the air in my car set to heat and it would shoot out cold air.....I would have to turn the dial to cold to get heat. Then it would right itself sometimes. The problem then became constant. Hot was cold and cold was hot. Now, all I have is cold air, no matter what I set it on. Checked my coolant level and it is fine. Could my thermostat be going or have gone out? Or, is this something I haven't thought of? Any suggestions as to what this could be, how to fix it, can I do it myself....and what is the estimated cost?

Thank you in advance.

If it helps, my 8 is an '04 with roughly 68,000 miles on it.

 

I had this happen last year. It was the control unit on the dashboard.

Do a search for heat control unit, and you should pull up several threads about it.

To diagnose: Look behind the dash under the steering column, and turn the temp control **** back and forth. The operating rod behind the dash should move incrementally with each change of the ****. If you need to turn it all the way one way or the other to make it move, then it is going bad. If the rod doesn't move at all, I guess that it is totally shot.

To replace: It is pretty easy and there is a procedure posted here that you can search for. I also think that there might be a TSB on it.

One thing to be sure to do: Make sure that you shop around for the control unit. They can be bought remaned and new, and the dealership that I went to really tried to ream me on the price. Do a web search before you buy for the lowest price for the unit. Best of luck