voiddweller

So I've got a strange problem. Not sure how long it's been happening because I live in Florida and always have the AC on.. This is what's happening.. in a warm engine condition..

AC Button ON Fan switch off, 1500 RPM Idle
AC Button ON Fan switch off, 1100 RPM Idle
AC Button OFF Fan switch on 1100 RPM Idle (AC Still blows ice cold)

I am now running the ac with the actual ac button off and the fan switch on, because thats where it idles where it needs to be.

I can't figure out why when the AC button is turned on, and the fan is turned to off it idles at 1500 rpm, and this is only HALF the time, sometimes it all idles at 800 where it belongs..

Ideas? I have no clue about AC systems. Vacuum line or relay? I looked under the hood everything seems ok. I did have an HG job done a while back, I'm not sure if this started happening after or was already happening and I just didn't notice..