Installing a 12 Volt Fuse Block
The time for Judy and I to head north to Alaska is quickly drawing near so we’ve been busy getting her van ready. One thing we needed was extra power outlets around her van, especially in the cab up front where one of us will spend a lot of time. Rather than do it piece-meal I decided to put in a fuse block. While you can wire all the appliances and outlets directly to the battery it creates a tangled, confused mess of wires and means running wires across the whole van for each item.
A much better idea is to put a fuse block somewhere in the middle of the van. That way you run a single 6 gauge wire from it to the battery and all of your other appliances are run to it. Plus each item is fused when you wire it so you don’t have to fuse each item individually. I bought mine from Amazon.com and it’s made by Blue Sea for boats. It has places for 6 fused items and 6 grounds for their negatives. You can buy it here: Blue Sea Systems Fuse Block – 6 Circuits
I’ve done two posts on very basic 12 volt wiring and I recommend you re-read them if you are new to wiring:
Step 1: You need to put ring connectors on the 6 gauge wire to go to both posts of the battery and to the fuse block. First measure to see how long the wire should be and cut it to that length. Then use your stripping tool to strip about 1/2 an inch of the rubber sheath off both ends of the wire. In the picture above you can see where I’ve marked “teeth.” You put the right sized wire in the teeth and squeeze down on the tool which cuts through the rubber sheath but doesn’t cut the wire underneath. Then pull that little bit of rubber sheath off exposing the wire below. You can buy a cheap all-in-one tool from Walmart for about $4 and it will do the job. I do enough wiring that I spent the money and bought quality Channelock tools. Good tools make any job easier! Channellock Wire Stripper and Cutter and Channellock Crimping Tool with Cutter
Step 2: Put the ring connector (it needs to be 3/8 so it will go over the battery post) over the stripped end of the wire and crimp it. In the picture above you can see that you want to squeeze it totally flat so the bare wire is gripped tightly. After you’ve crimped it tight grab the wire in one hand and the connector in the other and give it a good tug. Don’t be shy really try to pull them apart. If it’s going to fail, you want to find out now rather than later.
Step 3: Connect the red wire to the positive post of the battery and to the positive post of the fuse block and the black wire from the negative post of the battery to the negative post of the fuse block. Then mount the fuse block wherever you want it and you’re done! While all your devices will be fused at this end they really should be fused at the positive post of the battery as well. I didn’t have a fuse holder when I did this project, but I’ll add one as soon as I can. You will want to fuse yours as well. You can use this fuse-holder from Amazon: Blue Sea Systems Fuse 30-80A
and use an 80 amp fuse: Rockford Fosgate 80 Amp Maxi Fuse, 2-Pack
Step 4: Now you need to put your shiny new fuse block to work. We needed more cigarette lighter outlets so the first thing I did was add one I had on hand with dual outlets. It’s a very simple job of stripping and crimping. I used 10 gauge wire because there were two outlets. There is a short red and black wire coming from the outlet so I used a butt connector to add a long wire which would reach up front. On the other end I used a spade connector because so that all I had to do is loosen the screws on the fuse block and slide them under the screws and re-tighten them. Easy Peezy!! I only had black wire on hand so I wrapped the positive wire with red electrical tape so in the future there will be no doubt which is positive.
Step 6: When you’ve screwed in all your items, put the cover on and you are done! We’re taking my Dometic 12 volt compressor fridge to Alaska with us and it’s cigarette lighter plug had failed so I just cut it off and crimped on spade connectors. It’s the other item I have wired in here. You can see I only used 2 of the available 6 circuits. So from now on to add anything all I have to do is strip and connect a spade connector onto the wire coming from the item, loosen the screws on the fuse block, slide the spade connector under neath it and re-tighten the screw. Very easy. The fuse block doesn’t come with blade fuses so you’ll need to buy an assortment and use whatever size your appliance calls for.
Once you’ve mastered the basic art of stripping and crimping wire, minor projects like this won’t be intimidating at all. Honestly, anybody can do it!