|Don't let this happen to you! Route those accessory wires away from heat and moving parts. Tie them up with zip-ties where necessary and finish it all off with a proper fuse panel.|
So the here is the scenario. I have a winch, a pair of spot lights, an air compressor, a fridge and all of the required bits that are necessary for all of these things to be safely wired into our Jeep JK.
I should state that although not terribly complicated, wiring your rig should be taken very seriously. It's a safety hazard at very best and, if at all possible, you should avoid adding extra complexity at all cost. This means that if you had a moment to yourself thinking, "I really like those rock lights, or man! That guy has a lot of LED lights, I bet I can get more ...yeah, definitely." Then perhaps it's time to take a step back and reconsider that next widget purchase and instead use that money for fuel for your next big trip.
Before you get all bent out of shape don't worry, there are some items you will find it hard to live without, and those are the items you should release those hard earned bills back into the economy for. Moving on.
Despite the potential fire hazard from running wires to your prized LED collection, reliability issues can be a factor as well. When you attach the illumination wire for your accessory switch to the factory harness in order for the switches to light up proud and pretty, you risk harming the factory harness. Sometimes manufacturers, for reasons unknown, will route power for one component through another. When I was a professional mechanic, there were times I found myself folding out layer after layer of factory manuals tracing wires through a complex electrical schematic only to find out the power to the rear wiper motor is required for the pop up headlights to well, pop up. Adding the bells and whistles that make us so happy can make the trouble shooting process even more difficult.
Having warned you, and having stated that I too have widgets, lets move on. If even after hearing me carry on you still want to add some widgets to your rig then the name of the game is "isolation". You want to create a separate electrical supply for all of your auxiliary items. The best way to do that is with a quality fuse block. There are many out there and I'm not here to tell you which one is the best (Blue Sea ...they're the best. No, really.), I'll leave that argument to the interwebs and just tell you what I have.
Blue Sea Fuse Block #5029
|Dimensions vary between 5029 models. Mine is 8"x4"x2" (203mm X 102mm X 51mm approximately).|
So how did I come to this particular model you ask? Well the first thing you will need to decide is how many accessories you think that you will be adding and then leave room to expand later. If you haven't already guessed, I don't really have plans to add much more so I went with a 12 circuit model. This gives me the flexibility I need to wire both accessory and switch power sources to a proper fuse. The next thing you will face is the amount of load that will be necessary to run all of those devices at one time. You simply add up your amperage totals, then look for a fuse block that can support this load safely. If you are unsure how to do this, or you are uncomfortable for any reason, the best thing to do is to contact Blue Sea directly and speak to one of their representatives. They will help to safely guide you away from that imminent fireball that all of your friends are secretly longing for behind your back.
One thing I would also like to point out, and it may seem odd or perhaps even a bit ironic, but your fuse block will also need to be fused. If for some reason the supply wire to the fuse block were to short or come loose, then that entire length of wire no matter how long or short will catch fire.
The 5029 I chose requires at maximum a 125 amp fuse. That's not to say I need to run that high of an amp rating, but this model is not designed to support above 100 amps and as such, I will keep my system within these guidelines (FYI, each circuit on the 5029 is rated at 30 amps max). Since my air compressor requires between 14 and 25 amps, I should be fine. Typically you want to fuse 25% above the maximum load (25amps* 1.25 = 31.25amps). That's close to the limits but still very safe.
Now that you have determined your load requirements and selected your fuse panel, the next step will be determining a suitable location to mount it. As far as fuse blocks go, it's all about location location location. It should be mounted as closely to the positive battery terminal as reasonably possible. The further the load has to travel ...nix that. Just trust me, mount it as close as you can to battery and you will be fine. It's not the end of the world if you have to mount it a few feet away. Just make sure that the supply wire is the appropriate size.
I'm choosing to mount mine between the battery and the passenger side fender. Luckily enough, there is enough room there and a couple of fender bolts that will hold a bracket nicely. Now that I know where it will fit I can begin planning out the method of installation. I am a big fan of making cardboard templates. They are cheap, easy to cut and are easily transferrable to the particular material you choose for the final product. For this occasion manilla folders were plentiful and nearby so that's what I went with.
Actually, I kind of did things a little differently than I normally would. I had a thin piece of aluminum that came with one of those Radio Shack project boxes I purchased so long ago -for reasons that fail to surface right now. I began by using a piece of paper and a pencil to mark where the factory hardware would pass through the bracket. I placed the paper over the heads of the bolts and used the side of the pencil graphite to create a rubbing of the bolt head placement. Then I marked the center and used the rubbing as a template to center punch the piece of aluminum (aluminium for you Brits). Next I drilled the holes starting with a small bit and working my way up every other size, like you're supposed to do ...nah, I jumped from the small hole to the final bit size like a proper rebel! With the holes drilled I then carried the aluminum sheet over to the Jeep and laid the bracket holes over the holes on the fender (I had removed the bolts earlier). The holes lined up perfectly!
All done! I wish it was that simple. As with any modern vehicle there were several bits of plastic and odd shapes to work with as well. So I began to mark the aluminum with a pencil to show where to make my cuts -I used a Harbor Freight electric angle grinder and cutting wheel to slowly reveal the bracket amongst all of that aluminum. Everything was going well until I made a mistake on where to snip a bit off and it was back to the drawing board. That's ok though, it wasn't a total loss and these things rarely are. I was able to use the remaining bit to lay out on the aforementioned manilla envelope and trace it out. Only this time with the correct shape. See how much easier it would have been to start with a piece of cardboard?
I still have to pick up a piece of aluminum to finish the project. If for some reason I can't source aluminum locally, I will move on to steel. It's a small bracket and the weight difference is minimal. My main concern was the ease of which aluminum cuts versus steel and painting will be necessary too. No harm no foul, either way I'll be plenty happy.
Here is where I am tonight.
|Here is the final bit traced and cut out of the manilla folder.|
I will be continuing this project soon so check back periodically for updates. Thanks for visiting Overland Essentials.