So I just bought a 2004 Trailblazer 4.2 with the On-Star and without the Bose system.
*please move this if I am in the wrong area or if it has been answered, I did a search to no avail*
But yeah, I've enjoyed it so far other than the stereo not working other than AM/FM which is fair as it is older.
So I decide to remove the stock stereo, which is when I learned of the class-2 wiring and all the bells and whistles that Chevrolet slipped in there.
I've messed with stereos and audio my whole life and have never experienced this sort of thing so naturally I removed the factory unit, ran my own power straight from the battery.
The headunit I have when off doesn't pull any major current so I wasn't too worried about the switched voltage till after it was all working.
So as soon as I put the new headunit in, the car starts misfiring so bad it sounds like a diesel while flashing the check engine light.
Which I thought maybe it was bad gas as it was perfectly fine to ALL bad that quick.
Also checked plugs, and wires.
Being paranoid I put the old radio back in, and it was fine.
Now what I am wondering is, if anyone has been able to bypass this without buying the full harness retaining on-star and all the other useless add-ons?