24 volt ARB Compressor Install (1 Viewer)

[racingjason]

I finally finished installing my new 24v ARB high output compressor in the HJ61. Because of all the AC lines and wiring I had to come up with a riser to mount the compressor on which also gives it some more distance between it and the turbo. (pics to follow).

So I wired the compressor up just as ARB indicated, flipped the switch and nothing. I took a closer look a the wiring diagram and my worst suspicions were confirmed; ARB does not make any allowances for 24v on the solenoids/switches/relays/etc. (they are all 12v) therefore it is a dual 12v/24v system no matter what. The diagram shows a centre tap for 12v on the diagram but because I was using my 12v/24v transformer for the switched 12v source the system was not grounding properly. I rewired it as shown in the attached sketch as it worked great. I had to wire the blue-white wire (dash lights) into the transformer as well.

Now I understand that ARB is keeping things simple by offering the solenoids/switches/relay as 12v but it certainly complicates things when installing in a 24v vehicle. I can however, comfort myself in that if I ever need parts there should always be 12v ones around. I just think that they should revise the instructions for 24v vehicles, I mean where are you going to get switched 12v let alone 12v dash illumination circuit on a 24v truck? I will have to send them an email. I hope the attached diagram helps someone else out in the meantime.

Anyway, now that the hard part is done I just need to run/hook up the airlines and the 61 will be locked front and back.

 

[Radd Cruisers]

You MUST wire it up as shown in the ARB wiring diagram.

There are diodes in the system that are designed to prevent back-feeding of the circuits.

The center tap current is totally negligible as it is just what is required to trigger the relays and light the switches is only mA in draw, and will have no affect on battery balance or the charging system.

It's really not worth your time and effort to try and re-think this.


~John

 

[Capitalguy]

Racingjason, John is right, I installed the same pump in my 24v BJ70, as per the same ARB diagram a few weeks ago and it works fine, I admit I was a little confused too when I saw the 12v markings on the switches. I've used it a fair bit the last few weekends with no problems.

 

[racingjason]

Thanks guys. Just to clarify, the wiring diagram shows two seperate circuits, the 12v switching circuit for the solenoids/switches and relay and the 24v power circuit which sends electricity to to compressor. (see orange circuit on attached diagram)

I have wired the switching circuit up to take 12v from the transformer. I found this way easier to and did not have to cut into the stock harness. The diodes remain functional and I have a battery balancer so the draw differential was never an issue.

The compressor motor itself requires 24v and is triggered by the 12v relay in the switching circuit. No other part of the system requires 24v.

To be fair I did hook it up as ARB suggested however, it was not grounding properly because the ignition source (12v) came from my transformer (my choice). After some thought I realised why and adapted the system. The system I have set up is very simple and works well if you have an easy source of 12v from your switched 12v/24v transfomer.

 

[fireball]

Bump!

Anyone else with experience wiring the 24V arb compressor? I am confused by the comments above and the wiring diagram.

I bought the 24V compressor for my 24V BJ74. The relays in the compressor and the provided switch are all 12V. That to me means that the switch needs to see 12V input, and the relay needs 12V to activate. 24V is flowing across the relay, but since it is a 12V relay it needs 12V to trigger it.

However, the ARB instructions for switch wiring, on page 14, tell you to feed the switch 24V ignition and illumination. That doesn't seem to make sense!

 

[fireball]

FWIW I just called and had a long chat with tech support, got transferred to their wiring specialist and he reaffirmed what the original poster did is correct.

The fan, switch and relays are all on 12V.

The compressor(s) are 24V.

The thin black wire can be run to 24V ground.
The switch wiring should go to 12V inputs.

 

[hoser]

The center tap current is totally negligible as it is just what is required to trigger the relays and light the switches is only mA in draw, and will have no affect on battery balance or the charging system.

With the CKMTA24 twin compressor, it seems the cooling fan also runs on 12V?? The current draw of that fan isn't a lot... but perhaps significant enough to cause an imbalance over time?

 

[fireball]

The fan is indeed 12V and it runs whenever the switch is on, regardless of whether the compressor is running. I had the thing apart last night and the amperage was stated on the sticker but I don't recall what it was. Nonetheless the switch and fan can conceivably be running for a good long while pulling 12V which I think *would* eventually cause an imbalance.

 

[Radd Cruisers]

With the CKMTA24 twin compressor, it seems the cooling fan also runs on 12V?? The current draw of that fan isn't a lot... but perhaps significant enough to cause an imbalance over time?

My original post was in regard to the smaller single compressors used for the air lockers.

Though I have a 24V ARB twin motor setup, I have not wired it up or looked at the schematic.

Most small computer style fans don't draw much, but again, I have not looked into how much current they use so you may have a point.

~John

 

[wngrog]

Digging this up.

I’ve wired the 24v compressor like ARB recommends.

Red + to Battery 2 positive

Black/white to to Battery 2 negative

Solid Black 5 amp to battery 2 negative.

The Powerprobe says I’m only getting voltage from Battery 2 at the 40 amp fuse.

Compressor has been tested with the powerprobe and it works.

 

[wngrog]

Fixed it.



Turns out the ARB diagram to use Battery 2 for positive and Battery 1 as negative is wrong. That only got me 12v. Reversed it and it’s working