Power Distribution System
Overview
I decided to create a power distribution system of sorts to provide a central place to power my various accessories. My goals were to make it easier to wire up new power feeds without having to continuously find inventive ways to tap in to existing power sources and to centralize power distribution as much as possible to make it easier to work with and troubleshoot.
Details
I decided that I wanted to have two different fuse blocks with one being a constant on power feed and the other being a switched power feed. As others have had success with the Blue Sea fuse blocks, I decided to use their products as well. I went with the 6 fuse ATO fuse panel with negative bus for both the constant and switched power feeds.
Given that the vehicle has a chassis ground the negative bus isn't strictly needed but I went with that model so that I could have the option of a clean ground path for devices such as my CB that can be sensitive to dirty or transient voltages on ground.
Both the positive and negative main feeds to the fuse panels are connected to the auxiliary terminals on my Diehard Group 31M battery with one positive and negative feed for each fuse panel. On the positive side the feeds come off the battery to a 125A ANL fuse. From the 125A fuse the feed then goes directly to the constant power fuse block while the switched feed goes to a 200A relay which then provides power to the switched fuse block. The 200A relay is triggered by power from a fuse tap off the in-cabin fuse panel under the driver side dash.
Pictures
A picture showing the layout while it was still being built out
A picture showing it after being completed
I used 4 gauge wire for the main power and ground feeds to the fuse panels. The 125A fuses, 200A relay and fuse panels are all secured with 3M VHB tape. I decided to leverage the large flat area on top of the engine compartment fuse panel as mounting locations for the 125A fuses and the 200A relay. I don't anticipate having to get in there very often so making use of that space was an acceptable trade off with the loss of easy access to the fuses inside. It's been a few weeks and the VHB tape still has everything very securely attached.
The silver L piece of aluminum you see on the far left of the second picture is a bracket I made to mount relays for my on-board air system.