My car's A/C had been going in and out intermittently. Sometimes I'd turn it on and it'd take 5-10 minutes before I could hear it engage and the air would get cold. Then it'd get warm and go another 10 minutes or so before I could hear it go on and get cold again. Anyways, the other day I noticed I had quite a bit of corrosion on my positive battery terminal, so I cleaned it and my terminal cable with some steel wool, and my A/C worked GREAT directly afterwards for a week or two, then it started going in and out again... and there's a little bit of build-up on the terminal again.

1) is it possible that the corrosion on the terminal would cause the A/C not to work all the time?
2) what's up with my battery terminal? The battery is a die hard (those are awesome, right?), a few years old. Does it need to be replaced or is there something else I should check?