Brett Kornowski

I have a 2008 Silverado 2500 HD. A few weeks ago my entire bank #2 went out while towing and caused an entire mess. Long story short, three weeks later when I had time to troubleshoot I found that the ground wire that bank was bad. Where does that small black wire go and ground? It apparently shares the same ground as bank #1 (determined after snipping wire and providing a new ground pre main coil connector). Obviously I have a broken wire or bad ground and want to know where exactly does this small ground wire channel to. Thanks.