My ac/heating control unit keep turning on the automatic function

What is your question?

I have been having this issue for a couple of weeks now. When the car is running I'll turn the defrost and floor button and after a few minutes I'll shut it off. No problems with that but then another few minutes later the automatic function kicks on by itself. I'll shut it off and it kicks back on maybe 30 seconds later. Is this a sign that I need to replace the control unit or is there something else going on?

What makes this problem better or worse?

Pulling over, shutting down, restarting the car seems to somewhat help.

How long has your 2004 Mercury Grand Marquis had this problem?

2 or 3 weeks