Looking for switched power + to activate sub amp located in trunk

My favorite approach to that problem doesn't require hunting down or tapping any switched circuits, but just mounting a small gizmo InPower makes called the VCM-06 right next to the battery (which, conveniently for you, is right there in back where you want your sub amp), along with whatever fuses I'll need for whatever I want to hook up.

The VCM can simply detect the rise in voltage when you put the car READY and the drop when you turn it off, and turn its output on and off accordingly. It has a few other nice features I've covered in the linked threads.



Hard to see the VCM-06 in that picture because I mounted it to the underside of the DIN rail. You can sort of see the screw heads. The silver flat telephone cable in the corner goes to the remote on/off port of the inverter.

You really do want the car to be in READY, not just ACC, when using any significant power. The battery capacity is not very large, and just being in ACC without any added stuff will drain it in short order.

As a recent update, I didn't see the VCM-06 in InPower's catalog the most recent time I looked. They have other similar modules, but I have to say I liked the -06 best, because of the configurable time-delay-off. Ah well.