I want to solve a very annoying problem I've had with the last two Sony car audio receivers I've owned. The problem being that days are spent getting all the sound setting perfect to my liking, which I write down, but if the battery needs to be disconnected there's no battery backup for the receiver's memory settings, so the settings are all lost. Astonishingly they don't have this feature, even for factory sound systems, but they do have it for home clock radios and the like. I tried one of those 9V battery connectors to the lighter, supposedly just for this purpose but it didn't work.
I bought a battery pack which will hold eight 1.5V AA batteries providing 12V and it has just a Black and Red wire to connect. The receiver's power related wires are Black (ground), Yellow (constant 12V to car battery, Red to accessory 12V panel (remote which signals the receiver On/Off when the ignition key is turned and Orange for illumination.
I'll only use the battery pack and connect it before the car battery is to be disconnected and not turn the receiver on. It's just to preserve the settings in the memory. Would the correct wire connection of the battery pack be Black to ground and just splice in the Red wire into the Yellow wire going to the battery with a connector?