NOTE: All wires other that the switch, battery banks and common ground are 12 awg. From the switch to the battery banks and to the common ground are all 4 awg. The issue I'm having is that without the accessory turned on anything connected to the ground is on. I would like to find a way to require the accessory devices to require the ground to go to the controller's accessory negative and not back through the battery banks. Understand that one of the items I'm adding has to much draw for the controller to handle (two audio amplifiers not yet installed) and they do require a common ground due to distance from controller and battery banks. Is the controller's battery negative and accessory negative supposed to be bi-directional? If so, how can I separate the grounds but keep them both common?