#23 The Van Has Electrics!

Over the last few weeks we have been working on the bulkhead, the bed and the electrics intermittently – instead of the chronological events, they will each have a post of their own – starting with the electrics!

First things first, 12v electrics aren’t too difficult to get your head around. Be patient and do your research and you should have enough knowledge to give your van some electric in the back. It can be quite daunting when you first look at the wiring diagrams which are widely available online or in forums but all you need to do is isolate the parts which apply to you and make sure you understand that – the diagram is a much simpler version of the real life mess of wires which you will be putting together. So the most used campervan electric diagrams feature all kinds of things which we decided we didn’t want or need, such as a fridge, 230v sockets, electric hook up and a mains battery charger.

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Getting rid of that portion of the diagram also gets rid of the danger element. No more 230v positive, neutral and earth wires only 12v positive and 12v negative! It’s still not risk free as you have to make sure that the wire you use is appropriate for the current which it will carry, fuses will also help you do this and should be used at key parts around the circuit, to make sure that you do not set fire to your van!

Without the use of electric hook up or solar power we will be making do with energy created by the alternator of the van itself to charge our leisure battery, this will mean we will only be charging the battery when driving the vehicle we decided this suited our needs as we rarely stay at any one place for more than a day or two. The way in which we charge our leisure battery from the alternator is by using a split charge relay which is used to regulate when our leisure battery takes electricity from our starter battery.

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The split charge relay connecting to the starter battery under the floor in the cab.

Essentially the split charge relay detects when the voltage of the van battery is high enough to share the charge from the alternator with leisure battery and then cut out when the voltage is too low, meaning the leisure battery will only be charged when the starter battery has a high enough charge to let us drive away in the morning. You could use a manual switch to do this too but the fear of forgetting to turn it off would add far too much stress to our travels!

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The wire then travels under the rubber flooring, behind the driver’s seat, tidily to the bulk head where it is needed. 

Now we can envisage a charged leisure battery which doesn’t negatively impact the starter battery we can start to think about wiring up some useful USB chargers and lights. All of our appliances will be fed from one blade fuse box and all of the negatives will come back to a common earth in the form of a negative bus bar. Everything will have a switch as well so we can turn things off when we are away from the van for a while. Now this is where the mess of wires comes in… my pictures will hopefully speak a thousand words!

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We have wired the 4 spot lights in pairs so one blade fuse carries two positive wires to our two light switches and these switches then carry a positive to the lights. The negative wires from the lights run straight back to the bus bar along with a negative from the switch and that is one complete circuit from the fuse box back to the negative bus bar with a light somewhere in the middle. All of our switches have a negative due to the small blue LED which comes on when the appliance is switched on, therefore requiring a negative to complete its circuit.

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Our switches on our prototype panel!

This same principle is applied to every appliance, one positive from the blade fuse box to a switch, one positive from the switch to the appliance and then a negative from the appliance and the switch back to the bus bar. It really is as easy as that, or it would be if it was just one appliance, here’s a picture of some of our wires which were then connected to our electrical panel. Making the wires for this was actually quite satisfying – We knew we needed 8 negative wires for the 8 switches and they needed to be the same length and have a spade connector on the switch end and ring terminals on the other end. Instead of crimping one ring terminal to each wire and having a very busy looking negative bus bar we used two ring terminals with four negatives crimped in to each terminal. Cable tying these looms and labelling them is an absolute must. To be honest even with everything labelled at each end it can get a bit confusing so the tip of the day was “take your time”.

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Eventually there will be a ply backing to the bulkhead encasing these wires.

So with lots of looms made up (one for switch negatives, one for appliance negatives and a couple for the appliances) it was time to connect it all up. It went well and was satisfying to complete. We ended up spending a few days getting everything tidy and neat, we were not really sure on the set up that we wanted around the leisure battery and also some of the wires were fractionally too short which dictated the end point. Our lesson from this – be generous with wire lengths. We are still not one hundred percent happy with the set up so currently the relay, fuse box and negative bus bar are not screwed in to place, for now however, it is secure and safe enough.

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Working on the electrics inside a van was always going to be challenging due to the limited space, even more so when you start fixing the furniture to the floor/walls and have to contort yourself around it to get to where you need to be. For ease, most of this was done with the front passengers’ seat removed from the van, that extra space made a significant difference! If we could go back and give ourselves some advice it would be: take your time and be methodical, create separate looms (cable tying and labelling them early as it is much easier to recognise 8 switch negatives if they are together), be generous with wire lengths as you may need more than your initial measurement and don’t be scared… enjoy it!

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