On board air with ARB single and bedside cubby mount

Hey, first attempt at a write-up and also first modification to the truck. There are a few pictures for proof, but feel free to ask for more if you have questions on how to do yours. Here we go.

Products purchased (~$495)

• ARB single 12v compressor (
  $338 ckma12 on-board air compressor high performance 12 volt for air locker differentials and tire inflation
  ckma12) +hose +deflator ($360)
• Expedition Essentials Bedside Cubby Mount ($115)
• Ch4x4 switch for cab (Amazon $19.94)

Equipment necessary for installation (~$60)

• 10 ga wire (Lowes $17.16)
• Electric tape (Lowes $4.84)
• Cable ties (Lowes $2.23)
• Anti-oxidant compound (Lowes $2.94)
• Solder (Lowes $9.44)
• Soldering iron
• Quick disconnects (male and female) for 10gauge and 18g (Lowes $2.95)
• Heat shrink
• Fuse taps (O’Reilly auto parts $6.29 ea)
• Wire cutters/strippers

Wiring

I’m only connecting the compressor to one switch because I’m not running lockers off of it. The ARB harness comes with 2 parts which are a big mess of wires, and a smaller mess of wires. The smaller mess is what goes from your switch that gets mounted in the cab, through the fire wall and then connects to the big mess, the main harness, via quick disconnect plug. I’ll focus on the switch first.

Because I have one switch for turning the compressor on and off, I don’t need two of the three switch bundles on the harness. To determine which one to use, follow the ignition wire on the diagram ARB gives you. It goes into the “isolation switch”. From there, your switch sends power out the red cable to the quick disconnect and is grounded via the black cable. The green and yellow have no role. You’ll have to connect the arb wires to your CH4X4 switch. Just put power in the top, power out in the second spot, dash in the third, and ground in the fourth wires of the switch. As for the ignition and dash lines, I have put mini fuse taps (add-a-circuit is what littelfuse calls them) on them and use 15 amp fuses when I tap into the bus by the brake pedal. Here's a snip from @Darin L

13) Pull the POUTLET2 fuse. Both are 15 amp fuses so it is impossible to screw up. Plug it in.

14) Pull the IG NO.1 fuse. Put the 7.5 amp fuse closest to the fuse box. Add the new 15 amp fuse furthest from the fuse box. Plug it in.

15) Pull the green CH4x4 switch block up through your dash switch location, plug it into the switch, and push the switch into the dash until it clips into place.

16) Connect your two black wires to the battery ground in the engine bay.

17) Connect your red wire to the red battery terminal bolt.
Your switch is ready to connect to the rest of the harness now. You'll take the switch wires from the ARB harness, tape 'em to a coat hanger and shove 'em through the rubber boot where Toyota has wires running from back right of engine bay into the drivers floor.
To get power to where the compressor is mounted in the bed, I’ll need to extend the battery’s reach. The ARB harness is not long enough to go from the bed to the battery. So I’ve decided to keep the ARB harness next to the battery and run my own wires along the frame of the truck to the back cubby, following the factory electrical system under the truck. Should be about 17 feet or so of wire since that is how long the truck is. I took the ARB harness, cut the ends off of what connects to the compressor (power and ground 10gauge and red and blue 18 gauge flag connectors) put a male and female between the harness and the extension then attach the ARB parts I just snipped to the back end of the extension so the compressor gets it’s factory shipped parts clipping onto it and won’t suspect a thing. Only thing I had to solder was wire that I cut too short and needed another foot to make it to the bed.

Mounting the compressor

I got the the single so it’s small. The EE mount is made to center your compressor in the box, single or double. Not how I intended to mount it but I’ve spent too much time in this goddam heat to care at this point. Some tips: take the compressor off of its mount, mount the compressor mount to the EE mount, then reattach the compressor. Drill holes in your truck bed around the cubby using EE’s template. Lift the mounted compressor in the metal box up from under the bed and have a partner put the screws in. ***My truck had metal all in the way of the left side of the box. Not the little thin metal sheet right behind the fiberglass in the bed, but thick quarter inch metal down by the bumper. It prevented the mount from being able to get into position without me just yanking and banging on it until I could get a screw in then use vice grips to get the other screws within reach. It was a bitch. Thankfully the EE box is sturdy.*** Now you can cut up your cubby, try and mount it, and figure out where you need to cut some more because your compressor hose connection gets in the way. Do that (I used a cordless dremel) and you’re done!

Future improvements will be some weather stripping or something to seal up the cubby face to keep out rain. It just bothers me to think about right now. I'd also like to put a lock on the box to keep my hose from being stolen. Nobody will be able to get the compressor off without unmounting the whole box and taking it from underneath and a locking door wont stop that.


Credit to: @Powder taco @Darin L @jrlin718 @Jeff@ExE @dweldy424 Y’all volunteered the right info, asked the right questions, posted the right pics, and were very helpful!

I am aware of the deteriorating quality of this post as I get lazier and lazier. Credit to those monster write-ups that helped me through this!

 

Shit well I hope my 15 foot wire reaches...

 

I would HIGHLY recommend putting a relay on that switch since those switches are only rated for 3 amps. A compressor draws much more than 3 amps

 

Nice job on the install!!!

 

If that's what you're after, then you can just stick with the ARB harness they send with the compressor. This was addressing how to make that wiring system reach the bed. You will be able to unbox your compressor, and literally plug it in and its ready for use if you want it and the switch up front. But without tapping into the ignition line, your compressor can be turned on at any time, regardless of if your truck is running or not. This will drain your battery pretty quick.

 

Doesn't the switch's power come from the relay already? Where are you suggesting putting the relay? I obviously know nothing about electrical systems, just copied what I saw. saving up for a switchpro for lights and such down the road

 

A relay has (normally) 4 or 5 wires. For a simple on off switch you'll use a 4 pin or a Single Pole Single Throw relay. You wire the two appropriate wires to the switch so when the switch is switched on the coil in the relay will be energized and pull the relay in which will allow for however many amps the relay is rated for to pass through safely. The other two wires go to the compressor and the battery. The relay should have a small diagram on the side to show you what pin does what and you should be able to figure out which pin should go to what from there

 

Guys... This whole "make my own extension harness" has been quite the undertaking for me (first time doing anything like this). I think I'm finally done. I have the same color for all the 10 gauge wire so I hope I lined them in the connector correctly... I also hope it's long enough. Anyways, here are some pics. I also am probably just going to wrap the smaller harness in electrical tape.

 

Yeah the neater you keep it, the easier it is to run it under the truck. Looks good, and yeah hope it reaches haha doing it the first time is the most painful, so to speak...

 

Simple question, I have the same ARB compressor and want to swap out their switch for the CH4x4 dash switch. The ARB switch has two grounds. Do I need them both? If thats a yes then I just wire those two grounds together and run a single ground wire into the CH4X4 which has only one ground input.

 

I know this thread is old but do you have any pics or info on how you routed the wires up to the battery terminal

 

Haha. Now you feel our pain.

 

Everything is still perfect!!

 

For the door mount was the inner lip able to fit completely inside? Mine seems to be too long for their box. The spacers they provide dont fill the space completely When it’s on the truck