I wanted to show off my install of a split fuse box into the rear headrest storage compartment of my Honda Pilot.
My requirements were to have a single fuse box that could supply both constant (battery) power as well as switched (ACC / Ignition) power. I also needed the power to be run as a new line, instead of tapping into existing circuitry, as I didn't want to run into issues with overloading existing circuits or robbing them of power that they may need.
- Bosch 75 amp 12 volt Relay
- Blue Sea Systems 12 Device Split Fuse Box with Cover and Negative
I came up with the idea to use the rear cargo area where the headrests are stored, below the floor in the back. I had the actual install done by a local car audio shop that had recently installed my aftermarket stereo and amplifier. They ran the power directly from the car battery in the front, using the firewall entrance on the passenger side. The power cabling from the battery has an inline fuse within a foot or so of connecting to the battery in the engine compartment. They then routed the power cable to the back, I believe by routing the cable first to the center of the vehicle, and then continuing straight backwards all the way to the rear compartment. A few small holes were drilled to let the cabling in.
The cable from the battery first connects to the constant power point, section "A". Then I ran a line from "A" to "B", except I installed a Bosch 75 amp 12 volt relay in this cable; thus "B" is now controlled by a relay. For the relay activation, I made a "T" tap into the power from the rear cigarette outlet socket.
Section "A" has constant power to the battery, while section "B" has switched power that comes on when the key is switched to "ACC". This works great for a rear dash camera with parking mode, as now I can provide both power leads to tell the camera when it is in parking mode vs. driving / full recording mode. Additionally, I have plenty of connections I can use for additional accessories, such as additional lighting, a cellular modem & WiFi hotspot, etc. I like having the ability to add and remove different devices, and knowing that I have a solid power and ground for the devices, where each device can use it's own properly rated fuse, and also having access to both constant and switched power, is really fantastic.
I also did a very similar setup for the front of my vehicle as well, placing the fuse box underneath the passenger dashboard. I didn't photograph that to show off here, only because the position makes it difficult to see and get good pictures of. The front fuse box also has its own separate power line going to the battery in the engine compartment.
I hope some of you find this useful as a source of inspiration for future projects. If you have something similar or end up doing something like this yourself, comment and let me know.
Rear storage compartment:
Bosch 75 amp 12 volt relay, mounted vertically onto the forward vertical side of the rear storage compartment:
Blue Sea Systems Split Fuse Box for 12 Devices with the cover off:
Fuse Box with the cover on: