My ac and heater will not work. First I noticed fog coming from the vents then about a month or so later the ac and heater just stopped working. What could it possibly be? Also the display panel which show my temperature setting went out also. So now I cant tell if the temperature is set to hot, warm, or cold nor can I perform the ATC test to get an error code. What can I do to fix this problem? Is that an wiring issue or will the ac control unit have to be replaced?

 

This is a 99 Chrysler 300m.

 

well u let one thing turn into several more from the sound of it.
what does not work as far as the ac and heat system fan inop no heat no cold all are separate system designed to work as one.