Generally when you are setting up a set of lights on your 4WD the temptation is to take it to an Auto electrician and let them install the wiring for you, whilst it certainly is the easiest option, it also means that you have no idea how it was installed and will have trouble trying to troubleshoot if something goes wrong on the tracks. Additionally, one of the factors determining whether to go to an auto electrician, is the cost of getting a “professional” to install your accessories.

Whilst the professionals do know what they are doing, learning a few of the ins and outs of installing wiring safely on your vehicle, will open up a world of possibilities for future upgrades like a dual battery system, a fridge freezer socket, and even installing an aftermarket reversing camera to make backing your 4WD up safer and easier in tight spaces.

A first time DIYer looking at installing some LED Driving light wiring might be like looking at the controls for a space shuttle, but for those who have trouble with 12v wiring it really is quite simple, if you think of electricity like water flowing through pipes and your battery and alternator as a sort of pump everything will start to make a bit more sense.

Because of the nature of electricity all circuits need to be, just that, a loop from the positive battery terminal, through the 12v accessory and through an “earth”, “ground” or “-ve”. Now there are things that will restrict the flow of electricity and if there are any “leaks” the circuit won’t be complete, this makes the metaphor much easier to understand, and also if the pipe is too small you wont get enough juice to your accessory.

There are many ways to rig up your new LED Lighting Wiring, our favourite is to trigger it off your headlight high beam with a switch into the cab to isolate your new lights from being switched on all the time.

To wire up a professional looking job you will need to run a fused wire (that is heavy enough gauge) from your battery positive terminal directly to your relay block. A relay is a small cube shaped device that can switch heavy gauged wire on and off just like a wall switch, and is operated by another lower amperage circuit using a relay, we can use relays anywhere we need to control big amounts of power, with another circuit. From our relay we can continue to run our heavy-duty cable from the positive battery terminal all the way through our relay to our driving light mounting position and into the positive side of a pair of waterproof Deutsch connector or connectors, using a Y-splice to connect a second deutsch plug if required. With the positive power hooked up, you now need to ground the circuit so when the relay is triggered the lights switch on. This part is simple, simply run a heavy gauge earthing wire (black) all the way from the black wires from your deutsch connector all the way to the negative terminal on your battery.

With the power side of your circuit complete you can now begin to wire up your switching circuit. With a multi meter you need to test where the circuit is flowing power when your high beams are switched on, depending on your headlight you will have a “positive” and a “negative” terminal on your headlight high beam bulb.

With these terminals sorted you can begin to create a switched loop from the positive terminal through your relay into the cab of your vehicle and back to your headlight bulb negative completing a full circuit when you switch on your high beams, it will transfer power through the relay to the headlight earth, triggering the power wires for your driving lights to switch on.

With everything wired up its time to test, when you toggle the in-cab switch on, you arm the system, with the headlights turned to high beam the driving lights should illuminate, and with the toggle off, they should dim, with everything working, you can tidy your new wiring harness with heatshrink and cable ties.

To save yourself a lot of guessing, and triple checking, 4WD Supacentre have produced a plug and play wiring harness which easily and quickly installs in just about any 4WD, with minimal hassle, all wiring terminals are connected crimped and heatshrink wrapped, ready to be literally plugged in for play. Once setup a wiring harness kit from 4WD Supacentre can be installed in a matter of just a few minutes and makes connecting a lightbar or driving lights a piece of cake, with no nasty surprises.

For more information about the full range of 12v accessories and auxillary lighting available head to www.4WDSupacentre.com.au call us on 1800 88 39 64 or visit one of our fully kitted showrooms to see the range in person and ask an expert all the best tips for your next gear install!