Thread: Wiring and plumbing an air compressor ?

come and have a look at my disco which is an endless air conversion.. It'll give you an idea...

but I basically gutted a 240v compressor for the control valve then used its ports to direct air front (straight to an under hood fitting) and rear (via a hose under the body and up through a hole in the floor behind the back seats)


were you going to go with an engine driven compressor or a 12V powered job?

Err..............................you actually want to increase the cabin noise in your Defender ?

I assume you're talking about putting a 12 volt compressor under the drivers seat. I would question the installation of a pressure vessel (air tank) in here though. Visions of catastrophic failure are not pretty.

Seriously though, if it's for tyre inflation you won't need to run any air lines, just a serious (fused) power cable from under the passenger seat (battery) to a relay connected to the compressor. A thin control wire to a dash mounted switch and a quick connect air line and connector to the seat box side panel (there's plenty of room to mount a female connector/plate here), and jobs right.

In the Oka I mounted an ARB twin cylinder compressor (basically under and behind the passenger seat) this way. I also bought an ARB extension air hose, curly hose and inflation tool which fit neatly in a bag behind the seat and can also be used at home off the 'real' compressor if need be. Long enough to reach all wheels on the Oka so no issues with the Defender. (The Oka is the same wheelbase as the 130 Landys, ie. 130").

The only problem with this setup was the crappy relays ARB built into this system, 100 Km down the Anne Beadell and the cheap, crappy Chinese relays had rattled themselves to death. If you have an ARB compressor you will definitely need to replace these relay(s).

As BK points out an engine mounted compressor with an under vehicle tank is a better setup but a heck of a lot more work.

Deano

Thanks Dave but Deano has it ine one - just a 12V compressor, not an endless air set up which though awesome is not what I NEED. Money better spent elsewhere.

Simple is better so I reckon that's the best way to go. Just wondering what pneumatic connectors etc I need to get....

Oh and I won't be IN the cabin when the compressor is running so all good.....

Originally Posted by DeanoH

Err..............................you actually want to increase the cabin noise in your Defender ?

I assume you're talking about putting a 12 volt compressor under the drivers seat. I would question the installation of a pressure vessel (air tank) in here though. Visions of catastrophic failure are not pretty.

Seriously though, if it's for tyre inflation you won't need to run any air lines, just a serious (fused) power cable from under the passenger seat (battery) to a relay connected to the compressor. A thin control wire to a dash mounted switch and a quick connect air line and connector to the seat box side panel (there's plenty of room to mount a female connector/plate here), and jobs right.

In the Oka I mounted an ARB twin cylinder compressor (basically under and behind the passenger seat) this way. I also bought an ARB extension air hose, curly hose and inflation tool which fit neatly in a bag behind the seat and can also be used at home off the 'real' compressor if need be. Long enough to reach all wheels on the Oka so no issues with the Defender. (The Oka is the same wheelbase as the 130 Landys, ie. 130").

The only problem with this setup was the crappy relays ARB built into this system, 100 Km down the Anne Beadell and the cheap, crappy Chinese relays had rattled themselves to death. If you have an ARB compressor you will definitely need to replace these relay(s).

As BK points out an engine mounted compressor with an under vehicle tank is a better setup but a heck of a lot more work.

Deano

Hmmm, I just 'upgraded' my (ultra reliable) single engine ARB compressor for the new twin donk model - looks like I'll be swapping out those relays tomorrow.

I ran my old compressor down the side of my drawer system (in a 110) without a tank and used the ARB air hose kit to reach either end of the vehicle. The single motor ARB compressor is extremely reliable as long as you don't cook it - ie stick to the recommended duty cycle.

The new twin donk model is under the rear passenger seat plumbed into the ARB allow tank, mounted under rear seat floor. Can't comment on performance yet but I wanted to improve flow so I could use small air tools if needed. Tank is plumbed using push-fit pneumatic fittings and poly airline.

Both installs used dash mounted switches.

I think the two main factors to a successful electrical compressor install are heavy guage wiring and don't mount em anywhere that gets hot.

On my Discovery I wired an Anderson plug at the front and the back of the vehicle. The compressor has a plug also. That way you keep the compressor in a bag in the back of the vehicle and just plug it in near where you want to use it.
Simple and cheap, plus you also get 12V power outlets to use for other stuff.

I fitted the earlier style ARB compressor to the 130 about 9 years ago under the rear seat in the storage box. Initially I brought an airline and fitting out the bottom of the box on each side, a little inboard of the sliders but the fittings would quickly start to seize up with exposure to the elements on a 2 week Moreton trip. What I found best was having them come out just inside the rear doors on the outer panel of the under seat box, well protected and easy access. The supplied ARB inflation hose can reach front and rear tyres and even the ones on the tandem trailer. As for wiring I used most of the hardware from the ARB supplied loom but rearranged it all so that the fuse and relay lived in the battery box, the switch is on the little oval panel below the middle of the dash. I ended up using a pneumatic ram with 2 end caps and the shaft removed as a storage receiver (also in the box with the compressor) as it was free. This setup works for me but isn't the fastest for inflating 4 255s and Dave's a/c compressor would probably do all 4 before mine's done 2. For me though the engine bay is already full.

My compressor on the 130 was mounted in the cabin behind the rear seats, but after the rear ARB locker became an oil pump, the smell of 500ml of gear oil washing around inside the cab convinced me to move it. It is now mounted on the LH chassis rail behind the cab. The previous owner had plumbed the vehicle with standard 3/8" flexible air line connected to outlets with jamac couplings that are mounted under the tray on each side just behind the cab, works well as a relatively short air hose reaches the wheels on each side. Would need a longer hose if towing.
All the hose, tees and couplings are easily gettable from an industrial supplier (as i'm sure you're aware), quality female couplings aren't cheap though.

My ARB compressor is mounted on the firewall to the driver/right side of the brake pedal box. I currently need to open the bonnet to fit the hose. I will eventually fit a hose outlet somewhere so I don't need to open the bonnet. The ARB is much faster than my previous truck air compressor. Quite happy with it.