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Wiring question for mounting ARB CKMP12 compressor.

pedrogb

Grenadier Owner
Local time
9:42 AM
Joined
Feb 13, 2023
Messages
169
Location
Townsville Australia
Hi all, I have an older model arb compressor that was in a box. I am mounting it under the back seat using the Euro Flo mounting bracket. I'm leaving the switch (mount modified) and the outlet in its original position until i set up drawers in the rear of the car.
My question is, as I am using the original wiring harness, which has + & - leads, do I connect the red wire to the power or to the ignition wire located under the seat, already wired to 40 amp fuse? Black lead goes to earth point in floor. I only want it to be available when car is on.
Can anyone explain this? In simple terms?
Thanks
Pedro
 
Hi all, I have an older model arb compressor that was in a box. I am mounting it under the back seat using the Euro Flo mounting bracket. I'm leaving the switch (mount modified) and the outlet in its original position until i set up drawers in the rear of the car.
My question is, as I am using the original wiring harness, which has + & - leads, do I connect the red wire to the power or to the ignition wire located under the seat, already wired to 40 amp fuse? Black lead goes to earth point in floor. I only want it to be available when car is on.
Can anyone explain this? In simple terms?
Thanks
Pedro
Hi @pedrogb

Are you referring to the 40amp spare/compressor circuit in an MY23?
I'm playing with that circuit now.
This circuit is fused at FI13 in the interior electrical centre behind the starter battery.
There are three wires:
Black. Earth.
Brown. +12v live to battery.
Yellow. +12v ignition switched.
I'm using the yellow wire to operate the NATO socket contactor so the NATO socket is live whenever the ignition is on.

When I test pull fuse FI13 the brown and yellow wires both lose power so the fuse is protecting the live and ignition switched circuits. However only the brown wire looks to be rated at 40amps (based on the wire sizes). Because you already have a switch in your compressor cable I would connect the red wire from your compressor to the brown wire and connect your black wire to the black wire, or direct to the body earth point next to the 40amp connection. That replicates how this compressor would normally be hard wired. If there is an inline fuse on your cable then keep it and connect before the fuse holder.

I know you only want it powered when the ignition is on but the yellow ignition switched wire does not look suitable to power your compressor which can draw 32amps. You can use the switch on your compressor to turn it on and off. You should run the engine whenever you use the compressor for more than a few minutes so you don't flatten the battery.
 

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Hi all, I have an older model arb compressor that was in a box. I am mounting it under the back seat using the Euro Flo mounting bracket. I'm leaving the switch (mount modified) and the outlet in its original position until i set up drawers in the rear of the car.
My question is, as I am using the original wiring harness, which has + & - leads, do I connect the red wire to the power or to the ignition wire located under the seat, already wired to 40 amp fuse? Black lead goes to earth point in floor. I only want it to be available when car is on.
Can anyone explain this? In simple terms?
Thanks
Pedro
Also remember ARB have their manuals posted on their website, that include wiring diagrams.
 
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OK thanks, do they have something specific to ARB compressor and the relay on that?
Sorry my mistake. I meant ARB website. I have downloaded the twin air compressor manual before. I remember it was hard to find. It is never easy to navigate the ARB website. Also try the ARB USA website that seems much better. Look under Support.

The Agile Offroad installation guide has wiring info they may help you. Second link below.

  • AIR COMPRESSOR INSTALL (using Agile Off Road Kit for single ARB compressor): tips for installation here, Agile's detailed instructions here;
 
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The US market doesn't have the 40amp compressor circuit so the Agile instructions won't consider it. And the ARB stuff is not Grenadier specific so it gets wired to the battery.
It depends how much you want to use this existing 40amp circuit.

@pedrogb Are you looking at the relay on the CKMP12 and wondering what to do with it? That's item 20 in this ARB pic.
The relay is being used so the motor operating current is not passing through the switch. The switch powers the relay. The relay powers the motor. If you keep everything on the compressor and frame intact and cut the battery clamps off and connect the red and black power leads to the vehicle you will be good to go. If you want to relocate the switch you will need to make some other wiring changes. Maybe later when you do a drawer installation.

Screenshot_20260217-084620.png
 
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