I posted last year about my HVAC system putting out only heat no matter what the setting was. When I pressed some different buttons after a few minutes it would go start working properly again.

Yesterday my AC was working fine. I stopped the car and a few hours later went back out to drive it and all it would put out was heat no matter what setting it was on. Even in the off position, it puts out heat. In AC mode it puts out heat. In economy vent mode puts out heat. None of the buttons are doing anything to make a difference. Even pressing all the different buttons doesn't make a difference this time.

1991 300d 233k