fixed air compressor

[mcdoogs]

I like the location of the Owl bracket, its a clever use of that space. I’d rather run the trigger to INT1 and use that to tie to ignition. But then there will be the hole in the bracket where the switch should be which would look crappy, or just put the switch there without wiring it up. Maybe I can rig up a blank for that hole.

 

[Airleader]

My solution:

Post in thread 'Adding a third battery.'

Jan 17, 2025

Found it. Has only a 40 A Fuse, so I take the Littlefuse free port with 300 A and changed the too big M8 bolt to a M6 screw:

From the original INEOS compresso outlet under the rignt rear seat I used only the ingition "+" for the ARB switch (also for the illumination). I used the ARB wiring loom and took the yellow cable from the unused diff lock plug1 for the ignition "+" and connected it to the RED-YEL and BLU-WHT cable at the other end.

• Airleader

Outlet and switch under the rear seats left and right (next weekends work):

 

[ORSO]

The ARB twin should be wired directly to the starter battery. This is because the alternator supplies currently directly to the starter battery and the engine should always be running when using the compressor. It can draw 80amps when under load which is very high current. If it is wired to the auxiliary battery then it is a longer current path as power from the alternator has to first go through the starter battery before reaching the auxiliary via the Ctek combiner. I don't know the position of the starter battery in right hand drive Grenadiers. It is behind the driver in left hand drive versions.

so you don't use the trialmaster's stock wiring that is on the top button panel?

I would like to install an ARB KCMA12 with a small tank and place them on the bisongear roof shelf soon.

I'm not very familiar with electricity so I would need detailed instructions on where and how to connect it.

thanks

 

[mcdoogs]

so you don't use the trialmaster's stock wiring that is on the top button panel?

I would like to install an ARB KCMA12 with a small tank and place them on the bisongear roof shelf soon.

I'm not very familiar with electricity so I would need detailed instructions on where and how to connect it.

thanks

So the power for the compressor aboslutely needs to come from the battery. Each ARB compressor draws 40 amps (so 80 amps for the dual compressor) and those switches are either 10 or 25 amps each. 80 amps is very high draw and you do want the engine running when airing up.

ARB compressors have trigger wires though that control whether the compressor is switched on or not. That can be wired to one of the overhead switches. I used INT1 for my under driver seat installation.

 

[ORSO]

ARB compressors have trigger wires though that control whether the compressor is switched on or not. That can be wired to one of the overhead switches. I used INT1 for my under driver seat installation.

ok, let's see if I understood correctly:

with the CKMA12 compressor come two bundles of cables. the shorter one is used to activate the differential locks so it is not needed.

the longer wiring must be connected:

1) relay (supplied)

2) compressor power supply

3) pressure switch (supplied)

4) switch.
Do you connect the black and red cables to the original wiring on the passenger footwell instead of the ARB switch? Is this correct?
Connection: black => black and red => purple?
what cable section do you recommend in mmq for the connection?
In this way the compressor will be activated with the INT1 switch.

5) battery. you connect to the starter battery.
are there two cables connected to the negative pole right?
what cable section do you recommend in mmq for the connection?

thanks


ps.
information taken from these two videos:

View: https://www.youtube.com/watch?v=S9yOAamRmJg

View: https://www.youtube.com/watch?v=A3qY4CrDonw

 

[mcdoogs]

From the bundled ARB switch wiring loom, you only need the purple and black to connect to the INT1 outlet in the footwell.

As a caveat, I don't have the aux battery so I cant help you there with specifics. What I would do if I did was disconnect the aux battery from the starter first before doing anything else.

As for the power, the big red fused cable(s) should go straight to the starter battery positive terminal. The black negatives can go to any ground. There is a suitable ground under the floormat in the left rear passenger area, right behind the LHD driver seat and in front of the starter battery. Here is an install video from Owl outdoors which shows the wiring to the battery and ground:

View: https://youtu.be/sF_Fb0NIuzA


Important: Make sure you respect the process to safely disconnect the starter battery before disconnecting the negative. Open the doors and wait ~15 minutes until all the lights turn off to be sure the vehicle is fully in sleep mode, then disconnect the negative terminal.

 

[GrumpyBastard]

From the bundled ARB switch wiring loom, you only need the purple and black to connect to the INT1 outlet in the footwell.

As a caveat, I don't have the aux battery so I cant help you there with specifics. What I would do if I did was disconnect the aux battery from the starter first before doing anything else.

As for the power, the big red fused cable(s) should go straight to the starter battery positive terminal. The black negatives can go to any ground. There is a suitable ground under the floormat in the left rear passenger area, right behind the LHD driver seat and in front of the starter battery. Here is an install video from Owl outdoors which shows the wiring to the battery and ground:

View: https://youtu.be/sF_Fb0NIuzA


Important: Make sure you respect the process to safely disconnect the starter battery before disconnecting the negative. Open the doors and wait ~15 minutes until all the lights turn off to be sure the vehicle is fully in sleep mode, then disconnect the negative terminal.

You are the only person I've seen on here using this compressor without having the AUX battery. Am I missing it? Or is the second battery not necessary to be able to run this?

 

[mcdoogs]

You are the only person I've seen on here using this compressor without having the AUX battery. Am I missing it? Or is the second battery not necessary to be able to run this?

The only benefit of the stock aux battery in this context is being able to run a dual compressor with the engine off and having a decent chance of not draining the starter battery too low to start the engine. However, I'd never recommend running an onboard ARB dual compressor without the engine on unless it was hooked into a classic 'house battery' dual battery setup where the house battery is lithium (so it can handle deep discharges) and the drain is isolated from the starter battery. It just draws too much amperage (up to 80 amps).

With the engine on, the starter battery will be fine running the compressor as the alternator is also activated and maintaining the starter battery's charge and powering the cars electrical components including the compressor.

 

[GrumpyBastard]

The only benefit of the stock aux battery is being able to run a dual compressor with the engine off and having a decent chance of not draining the starter battery too low to start the engine. However, I'd never recommend running an onboard ARB dual compressor without the engine on unless it was hooked into a classic 'house battery' dual battery setup where the house battery is lithium (so it can handle deep discharges) and the drain is isolated from the starter battery. It just draws too much amperage (up to 80 amps).

With the engine on, the starter battery will be fine running the compressor as the alternator is also activated and maintaining the starter battery's charge and powering the cars electrical components including the compressor.

Thanks! I appreciate your explanation.