Wiring question for mounting ARB CKMP12 compressor.

[pedrogb]

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

 

[Clark Kent]

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.

 

[pedrogb]

Perfect. That's what I was kind of thinking but always ask first. Lots of people have done it before me. Many thanks

 

[TheDocAUS]

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.

 

[pedrogb]

OK thanks, do they have something specific to ARB compressor and the relay on that?

 

[Clark Kent]

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.

 

[TheDocAUS]

Just forget anything I said! I deleted the post to stop anyone in AU getting confused.

 

[pedrogb]

Yep that's my plan. Keep it simple. I modified that original bracket which holds switch and relay, means I don't need to modify wiring much. Just wondered if the relay rewiring would assist re on off. I'm more worried about it being turned on accidentally than anything. Thanks for your help Clark Kent and The Doc Aus

 

[Clark Kent]

Yep that's my plan. Keep it simple. I modified that original bracket which holds switch and relay, means I don't need to modify wiring much. Just wondered if the relay rewiring would assist re on off. I'm more worried about it being turned on accidentally than anything. Thanks for your help Clark Kent and The Doc Aus

I think you'll hear and feel the compressor running if you accidentally bump the switch on but if you still want to configure it so it can only operate when the ignition is on/engine running that's doable with the existing compressor circuit but it's less simples.

Black wire: No change.
Brown wire: Insert a 12v 40amp relay between your compressor red wire and the brown wire.
Yellow wire: Connect to the relay trigger circuit.

With a standard normally off relay:
Terminal 30. Brown wire (+12v live)
Terminal 85. Ground
Terminal 86. Yellow wire (ignition switched +12v)
Terminal 87. Compressor red wire
Compressor black wire connects to ground.

In this configuration when you turn the key on the relay will close and provide power to the switch. When you turn on the switch the compressor will operate. If the key is off turning on the compressor switch will do nothing.

This is a relay wiring example so the colours are different.
The green wire = circuit yellow wire.
The red wire = circuit brown wire.
The purple wire = your compressor red wire.

 

[pedrogb]

Legend. That's what I was after. I just don't do enough of it to understand how to set it up myself. I'm just waiting for humidity to fall below 80 % before I start working on the car outside.

 

[Clark Kent]

Happy to help.

Our son lives in Mt Louisa. We've visited enough times to know we couldn't live there. Dry heat we can handle but that NQ humidity!