When you buy the ARB dual air compressor it comes with a wiring harness suited for dual air lockers using a master switch. Great for the limited market who run dual air lockers, not the best all-round wiring for those who want a simple on / off air compressor for tyres and general use.
The ARB dual compressor comes with an in-built relay, making it easy to wire. All you have to do is switch the one coil wire, the rest are for switches that have back-lighting. Hook-up the power to your switch and one switch wire. That’s it.
The default wiring harness must be hacked, one way or another, the best thing you can do is lessen the nonsense wiring in your vehicle. Don’t try and leave all the connectors in place if you have no intention to ever use air lockers. Also, the diodes are still needed. Obviously if you plan on installing air lockers in the future, then hack it carefully with everything intact so you can easily correct when air lockers go in.
Important: Diodes are a one-way device allowing electricity flow one way only. They’re installed for the compressor to stop leakage back through your system when the motor starts. They must be installed in the correct direction, otherwise power will not flow.
Hot Tip: Parallel wiring and fuses are legal and acceptable, however, if you can I would recommend a single 80amp fuse. Ensure you cut the positive wires to the same length, its important with parallel wiring that the wires are the same length, thus the same resistance. This is not required for the ground wires, as they serve a different purpose than the parallel positives, however, if you cut the ground wires back you will find two joined into one, and for the two, the same rule applies if you go that far. The positive and negative do not need be the same length, just parallel wires of one type so they both distribute the current equally.
To give an example using my Dmax, I have my switches in the cabin, pictured below. I run from my power source, into the cabin switch, out of the cabin switch through the diode to the compressor purple wire. Push switch and power flows to turn on ARB in-built relay.
Thanks very much for such a timely and helpful reply on YouTube. I’ve done a lot of YouTube watching, but have never reached out. I did reply on YouTube just uncertain if it went through.
I want to get to this in the next day or so, it will be one of the last aspects of my build – Toyota Tacoma which I have been working on over the past 7 months, from suspension, RedArc, Dometic, on board water, etc.
I have the compressor, it just came yesterday, Your sharing may help with some of the head scratching. It will be installed in the bed arrangment of the truck.
Thanks again.
William
Bellingham, Washington, USA
Glad it helped William.
Hi Anthony,
I have watched your video & found your site, but I am still trying to figure this out. I just want to use the ARB switch that came with the compressor and mount the switch in the engine bay using a simplified wiring set up for now.
So you leave the switch harness plug (at the compressor) alone correct? In other words you connect the end of the purple wire opposite the compressor to the diode wire (after cutting it where it ties into the switch harness) and using that end (cut end) spliced to the purple wire. I think I have that much, but correct me if I am wrong please.
This is where I get confused, but I think I also then need a 12v power (off the battery or hub) to the switch with the other connection to the switch being the purple/diode wire just created above. Is that all correct? Just not sure where to make those two connections to the switch, but might be able to determine that on the ARB schematic.
Your help & direction is greatly appreciated!
Thank you!
Hey Keith,
Mate, you are spot on. Correct on all counts. You understand exactly what you’re doing.
Yes, you just need power to the switch, whether that be direct from your battery OR if you only want it running when the vehicle is running, then ignition power. You run out of your switch to the diode (which connects into the purple wire). It is only switching power, so just switching cable is needed to power the ARB internal relay coil, which switches internally the power cable you have running to the compressor (large sucker).
The switch can be on either side of that diode, as long as its in there, its doing its job.
I connected my diode output directly to the purple wire. I ran power into the switch, out of the switch output to the red/yellow diode input.
Great and informative write up! My truck has built in upfitters, so I don’t need the illumination circuit either. How many amps does the fuse for the switch circuit, back to the relay need?
1A to 3A fuse is more than enough. The switch wiring for a relay coil is typically around 100mA, so the smallest fuse is typically more than enough.
Hi Anthony,
awesome vid, can you tell me if this can work on a negatively switched switch panel? (the Safiery touch switch panel )
cheers Brett
Hey Brett, this won’t unfortunately, because you are switching the existing positive wire coming from the compressor. The compressor has no negative to pickup from for on/off, as that is internally wired to the primary 80A ground.
You could, if you wanted to add a relay, place this positive line onto a relay switch and then switch the negative on the relay coil. Same outcome, just an added step to achieve it.
Hi Brett, watch the you tube and read the comments etc here. I also have the twin ARB but have kept all the wiring harness as i may want air lockers done the track. I have the compressor in my under tray tool box in my LC79, got all the power sorted direct to the start battery with heavier gauge wring and waterproof fuse. Wanting to run the compressor only when the car runs and I have also extended wiring to the cab for the switch to be mounted there. My question is can i just get switch power ( red/yellow wire) off the Fuse board in the passenger foot well by using an Add A Fuse of the cig lighter or whipper spots ( being the ignition is already taken by another add a fuse when i got the car ( maybe the reversing camera?) I also want the switch to illuminate when the dash lights are on – so i considered putting the dash wire ( blue/white) spliced to a neighboring switch wire which i think on the car are green wires.
Any help would be appreciated
Yes, you can get the switch power pretty much anywhere, as it is relay coil power only (100mA).
Hi Anthony,
Can I run the Red/Yel off the fuse box , I was using the fuse number 28 as show in the JTS12volt.com.au website and the dash illumination direct from the main battery
Thanks
Peter
I have a Ranger Wildtrak 2017 model
Mate, you can run the relay power from any positive source. You can even run it from the same source as the motor power if you want, but the key thing is that you want a switch in there so the unit isn’t obviously always on and you want the relay power fused with a 1A – 3A fuse.
I like to be super safe, which includes not allowing anything to drain my start battery, so me personally, if using a start battery system to power the compressor, I would run the switch wire from an ignition source, so the vehicle is running for the compressor to be running, so nobody drains the battery from starting.
Cheers, might look at putting in a switch or run it from the cigarette lighter source with a fuse in between. This hopefully should work?
Hey man thanks again for the video it’s incredibly helpful. I too am confused by the red and yellow. If originally the purple wire coming from the plug on the compressor went to the red wire that eventually ends up at the isolation switch as in the wiring diagram, can I just run the correct end of the red yellow wire and the red wire together into the purple wire?
Hey Joe, the source of the power is irrelevant, its how the connection is made and in what order to ensure stray currents when the motors start don’t come back down auxiliary wiring, ie. the diode is used in the switch wire. So yes, you can tap into the battery wire and connect the correct diode end of the red yellow to it if you want. Obviously a switch should be in place somewhere, or isolation.
Here is the simple explanation of why the wiring is done how it is. The motors run direct to the battery because a battery acts like a capacitor, being that it will handle motor thumping and stray currents just like a capacitor does. Most people will pull the switch power from elsewhere, thus the switch power is now connected to other sources in the vehicle which will contain sensitive equipment and without the diode isolation, stray currents may damage such sensitive electronics.
Basically, if you stray from any standard wiring techniques, you just need to know what you’re doing to counter any negative affect. There are multiple ways this can be wired, then there are old vehicles that have no sensitive equipment to damage and thus a stray current will simply end up back at the battery via an alternative route, doing no damage and the battery removing it once reached.
Saying all that, a battery can’t be relied upon to remove a stray current alone, ie. switch and motor power direct battery connection, if installed in a vehicle with sensitive electronics. Hence a diode stops it to begin with and keeps such stray current within the motor circuit designed to handle it. Electricity travels the shortest path, always, so things not seen or understood can vary how it acts.
Hey Anthony,
Thanks to your video, thank you for a great video; I now have a working compressor. Simple and concise instruction: I just had to increase the length since the compressor mounted to the other side where the switch panel is located.
Glad it helped.