2004 Sierra A/C

[Whatthefarm]

I was changing the stereo in my sierra and when I unplugged it, i heard a pop and all of a sudden the air conditioning started blowing heat. I haven't figured out what the heck happened. I tried changing the "a/c comp" fuse, which was a red 10a. That didn't do it. Any ideas? I really don't want to go to a mechanic for something like this.