A/C Issue after AM Radio install

[Hoefje77]

I recently installed an AM radio in my '07 Sky, and now the range on my A/C doesn't work. In it's coldest setting it blows cold air. If you move the dial one position clockwise to a warmer setting, it blasts the heat. There is no in between. Has anyone else had this problem and found a solution? The AM Radio was a Jensen 6.5" Monitor Radio and I had to hook up an OnStar Module to it to allow for OnStar to continue working. Nowhere in the wiring diagram does it say anything about A/C wiring (unless I missed it). The AM Radio plugged right into the harness that I unplugged the stock radio from. Any advice would be appreciated.

Thanks!