12V DC Wiring

Above is a diagram of my 12 volt wiring as it is right now in 2020. I have made several changes over the years. For one, I've installed an inverter and smart charger, both of which require heavy gauge wiring to the house batteries. Both of these are physically located under the second row passenger-side seat. I removed the original low-end charger/converter that was located under the rear drivers-side bed.

I have protected both positive take-offs from the batteries with class T-fuses. These should ideally be within 18 inches of the battery, but I had to mount mine a little further due to space constraints. One of these is positioned in the space under the toilet, and the other is attached to a rear bumper mounting bracket, under the back of the van. I bolted the fuses directly to the cable lugs rather than use a dedicated fuse holder to save space, and protected both of these fuses using plumbing parts to build small enclosures.

I also installed cutoff switches to both positive battery lines. This enables me to effectively isolate the batteries from the rest of the system if I need to work on the 12V system or when I put my van in storage. This will guarantee that there is no current draw on the batteries. I used Blue Sea Systems Mini Battery Switches, which are rated at 300 Amps. The Blue Sea products that I've purchased are of very high quality.