I wonder if there is a potentiometer back there being turned by the AC control. It really sounds like a dirty pot. I would try rotating the AC control back and forth rapidly for 10 -20 rotations, see if the problem becomes less frequent. If that works, some tuner cleaner might fix it. This is of course assuming there actually is a potentiometer back there...

 

Anyone know where I can buy a new connection ribbon or a whole new controller box? My AC or heater stays on CONSTANTLY. I am about go crazy with this thing...