About a week ago I started noticing that if I turned the AC or heat on that I would get a faint burning smell under the hood. I left it off most of the time but every once in a while I would turn it on again and get the same result. Yesterday I turned the AC on and it did nothing for a couple of minutes and then I started hearing a squealing sound. I turned the AC off immediately and it stopped. I have an 08 4x4 CC. I changed the drive belt about two weeks ago and the old belt looked good without any signs of wear. So, no problems unless I turn on AC or heat, then burning smell and as of yesterday squealing. I assume that if it was the idle pulley that it would do it all the time but that may not be accurate. Is it possible that the pulley for the AC is going bad?