On Board Air OBA using EAS

[maxrover]

So I am sure this has probably been discussed plenty but I am not finding eaxactly what I was hoping to find in my search of the forums.
My 95 LWB has a spring conversion and the PO left the EAS reservoir, pump, and I think everything else in place so I wanted to convert the tank and pump to make an On Board Air system for tire inflation, etc.
I saw the East Coast Rover page for their system and wanted to do something similar. Can anyone point me to something more detailed about the process. Surely I do not need to reinvent the wheel on this project. I was also hoping to learn from the experiences of others who have already experimented with where to put the lines, etc so that they are most convenient.

[lwbblue]

saved from an earlier post:

Air Compressor posted by Greg French on 01/15/2005 10:40:57 PM:
Greg - I haven't made the conversion yet myself, but a Land Rover Master Mechanic gave me the following instructions for converting the air compressor to work as an air pump:
Yes, it's the stock compressor and tank. You just use a jumper wire with the correct sized pins to jump two pins of the EAS ECU connector[harness side with the big connector] or solder a jumper wire to the back-side of the connector/pins once you've taken the outer plastic housing off and exposed the inner guts. This wiring job allows you to use the "inhibit" switch located on the center console,'93&'94 models/or dash for the '95 Classic as your compressor "On" switch. The pins to jump with the wire are pins #8 and #29. Pin 8 has a yellow/blue wire going to it, and pin 29 is a grey/yellow wire. With this, you're directing 12 volts to turn on the compressor relay instead of the old, now missing ECU via the middle EAS switch[inhibit switch] You must plan on installing some type of safety though for the system, as you can't use the old pressure switch which used to be the ECU's clue as to when to turn the compressor off.
I handled this in two ways, first I use an air hose that has a psi gauge in-line in the hose, so I can keep an eye on the system pressure. Second,I mounted a relief valve that blows at 150 psi where the stock tank mounted pressure switch was, you don't have the fitting on your tank as LR moved the switch over to the valve block for '95 and later RRs of both body styles. So, you can plumb in a tee fitting with a reducer bushing for both the coupler and a safety valve at the end of the tank with its 1/2" pipe thread plug, or add a different type of pressure switch that goes open when you reach the max pressure, and wire the new switch into the existing compressor relay under the passenger seat to open the ground circuit when max pressure is reached.

In case you're wondering why you can't just use the old stock switch, LR uses a switch that CLOSES with the high pressure limit to signal the ECU, and this is harder to wire into the system for what we want with the ECU now out of the picture instead of them using the more common switches that would go OPEN and stop a system from operating when max pressure is obtained!

[lukeisaduke]

I recentely just completed my installation of my onboard air system using the original sanden compressor. I am going to start a thread with the complete installation.

[maxrover]

Thank you lwbblue for that nugget. That was just what I was lopoking for. I will dig into it this weekend and see what kind of results I get. I may find that the pump is shot anyway but it would be novel to retain as much of the original gear if possible (just because I am cheap.) Later if it proves useful then I may try to upgrade the pump.
I am torn between an under-the-hood or in-the-boot arrangement for the quickrelease coupler and hose.

[lwbblue]

thanks maxrover. it's fun to save some of the good posts; never know when someone can use it.

regarding connector and pump placement; my vote goes for anywhere except the back. inside you might have to unload alot of stuff to use it. outside more dust/dirt/mud sucks up there than elsewhere.

under hood at least is a stable environment. mines under the gas filler door. a little tight, but protected.

[maxrover]

The gas filler is a nice discreet location. Probably a plumbing challenge but worth the effect when you pull out the hose and top off the tires at the gas station.

[roverandom]

There is a good write up for tapping into the EAS system in the 'upgrades' section on rangerovers.net

I have an ARB compressor in the back of my Rangie (to power the lockers) so I made a connection to add to it for tyre inflation. The connector is also inside (in the rear) because I wanted to keep it clean and protected.
While it works well one thing I did not foresee was the fact that in order to prevent running down the battery when airing back up I let the engine run but as the connector is inside the rear liftgate has to open and exhaust fumes enter the cabin.

I like the idea of placing it next to fuel filler, perhaps when I get time I will relocate the connector.

Hope that helps.