I don't know if anyone has figured this out, if they have, mods delete the post, but the 2010 cobalt doesn't have a ignition switch to turn on a head unit and I didn't want to run a line from the head unit to the fuse box. SO I used a multimeter and I fgured out none of the pins on the harness from the vehicle work, so I found out through the airbag light. The airbag light only receives 12v power when the key is turned to ON. Its the second pin from the left. Here's some pics. :nahnah very ghetto but it worked haha