Kicker Subwoofer install / Check engine light issue

[Jackwards]

Please, feel free to flame me. It’s late and I’m calling it a night because I’m sure I’m missing something simple.  

 

Started installing the Kicker subwoofer it from GM tonight.  

 

Ran the harness tonight, connected (without fully installing the box), connected and had sound.  Disconnected and put the box away for the night.  

 

 Two questions:

 

1) ended up with a check engine light (P25A2- engine electrical / chagring system & C0580 - Traction control error) after everything was run.  OnStar says there’s a charging system issue.  Anyone else encounter this?

 

2) Rear door speakers have nearly zero sound. Extremely low volume, and extremely light sound (zero bass, almost all highs).  Fronts sound fantastic. 

 

 

Sorry and thanks in advance for the help everyone. 

 

Edited May 16, 2019 by Jackwards
Updated info

[z1boss]

Might want to check this forum post out.  I haven't added a sub but maybe someone on here can help.