I just started using my AC and noticed that it wasn't blowing cold air. The EC (economy mode) light was on. I know this disables the coolant, so I tried to push and shut it off. It will not shut-off. This happened about 5 years ago, and was fixed. i didn't pay much attention to exactly what was done and cost, since it was under warranty. Can anyone give me some advice and what kind of repir bill to expect? thanks