I have a 2009 Saturn Aura XE that I'm trying to put a new radio and subs in. I've connected the harness correctly and it doesn't power on. I know I have the correct one because the other one activated the security system. The radio I'm installing is the Pioneer AVH-X390BS. I've already tried grounding directly to the chassis and the stock radio still works so I don't think I blew a fuse. I'm out of ideas and would rather not spend the money on getting it installed.
You will have to spend a little extra and get the correct harness adaptor because there is an external amp built into the system along with steering wheel volume control. Without the correct harness you will not get any power and/or sound. We can all thank GM for this integration :(