Mod 7: ARB Twin Air Compressor

Air is surprisingly useful when you’re out in the wilderness. On my previous 4Runner, I installed the ARB Twin Air Compressor so I could easily air up my tires after a day of offroading and hitting the trails. It became invaluable when I was on my 2 week overlanding trip through northern Canada, as the dirt roads were so rutted out that airing down was almost a necessity for a smoother ride. Without a compressor, I would have had to wait for a gas station to come over the horizon and hope they had air for me to use…

This time around I decided to iterate upon my previous installation and make it even more useful. I received a mount from a small fabricator known as “Bandiworld” on Instagram and the 4Runner forums. He makes custom ARB compressor mounts that fit like a glove in 4th and 5th gen 4Runners. We exchanged a few messages and within a couple of weeks, I have my custom mount for Po.

I decided to order a mount that allowed me to hold an air tank below the compressor as well. Being able to store air is not only useful for making air-ups faster, but they allow you to run small air tools and simply use some pressurized air without the compressor running at full-tilt all the time. I have found this incredibly useful while mountain biking as well. As we roll in to a trail head parking lot, I can let the compressor fill the tank and turn it off, which gives us plenty of air to inflate tires as needed before we hit the trails.

The install itself is fairly easy, but time consuming. Clearances in the passenger side corner of the engine bay are so tight that installing and removing can take quite some time. I had to test fit and remove the compressor three or four times just because I wanted the final install to be perfect. If you do this mod, I HIGHLY recommend you take out the airbox. It is just a few bolts and it gives you so much more room to be able to install this. I tried installing a few ways, but found the easiest way was to put the mount together, install the air tank on to it, mount it in to the truck, and then mount the compressor to it. Easy is a relative term here, but I have been able to take it apart and put it back together in about 20 minutes now, so I think it is pretty easy.

I ended up running leader hoses from the ARB to the tank, and then the tank to a manifold. The tank has 4 fittings, so one is for air in, one for air out, one for a dump valve, and one is plugged. I then installed the manifold and have a safety blowoff valve on there as well as a quick disconnect for an air hose. I opted for the manifold because I may run an airline to the rear eventually and wanted the option for expandability.

And finally, the wiring. What a pain in the butt. I wired the compressor to an Air On Board (AOB) switch and was confused left and right. It took me three different wiring schemes to finally get it how I wanted it to work. I wanted the AOB switch to obviously control the compressor, but also dim with the dash lights for a clean and factory looking install. If anyone has questions about the wiring, I listed out what worked for me below.

AOB Blue - Connect to ARB Blue/White
AOB Black - Connect directly to factory gray wire on wiper heater switch
AOB Red - Connect to ARB Red/Yellow
AOB Green - Connect to ARB Red

ARB Black(x2) - Tie both wires together and ground to chassis.
ARB Blue/White - Connect quick disconnect end to AOB Blue. Connect diode end to factory green wire on wiper heater switch.
ARB Red/Yellow - Connect quick disconnect end to AOB Red. Connect diode end to fuse of your picking on interior fuse box.
ARB Red - Connect directly to AOB Green