Thread: ARB compressor install into Disco 2 rear quarter

So, I grabbed my cheap ebay portable compressor to pump up the caravan's tyres and the on/off switch died. Started pulling it apart to fix and really noticed the absolute crap quality of the unit so I decided to get a new ARB compressor for my D2. It is only for tyres and not for lockers so I decided to fit into the LH rear quarter. I decided against the portable one as I don't have drawers and its just another box to annoy me when I hit the supermarket.

First was to remove the LH inner plastic panel and check it out. There is a black brace bolted to the wheel arch which I decided to adapt to make the mount. I ended up getting a bit of scrap 3mm plate and tig welding this to the back of original brace, then welding the ARB supplied bracket to this. A lick of black paint and bolted it back gives a good mount.

I attached all the pump connectors & bolted the motor onto the new bracket to line up the charging outlet to the standard vent.

Next was to take a look at the wiring supplied with the unit. Quality is good however I question the 40a megafuse location so close to the pump itself. This should be as close to the battery as possible to isolate any potential shorts. I left as is for the moment but I will get a new fuse in addition to standard one and fit close to the battery.

Apart from the main pump + & - supply, the harness requires both ignition power and illumination input to make the switch visible at night. My D2 is the base model so doesn't come with rear 12v accessory outlet however the wiring is still there. Quick solder and thats sorted. The main power supply I ran down the LH side under the scuff plates and kick panel, turned right to go behind the dash (behind air con control area) and out a blank grommet above the accelerator pedal to battery power. Its essential to use convolute tubing, tape & cable ties to remove any possible movement in the cable which could rub through. Especially near sharp body paneling behind trims etc.

It was decided that the compressor on/off switch would be in the boot area also. This was to reduce cabling from front to back of the car plus its only for tyre inflation so best to have the switch where the action is. I know if the switch was at the front I would forget to switch on & have to run back and forward!

Overall not a hard job so long as you have a welder & basic tools. I did initially try and wire up the main power to the 12v socket power supply noting that this was on a 25a fuse & ARB pump specs note a max 25a draw but it blew the fuse when under heavy load hence the full power cables running to the battery.

Pics 1 & 2 - Modified original bracket behind plastic panel. The vertical piece is scrap & the rectangle piece with 4 holes is the original ARB supplied one.
Pic 3 - Brace with new bracket installed
Pic 4 - If you don't have a 12v outlet, you will have a wiring harness exactly like this. Not connected, just sitting there. This has ignition power, earth & illumination power.
Pic 5 - Relay installed on a bolt that was already there. Test fitting wiring positions.
Pic 6 - Vent cut showing outlet
Pic 7 - Compressor switch installed here to avoid accidental knocks from cargo & within easy reach
Pic 8 - final product

Originally Posted by Tombie

Neat job - Well done...

I really enjoy the threads where people integrate the vehicles and dont butcher them...

Thanks Tombie,

I love cars that are discreet in their abilities