Thread: Endless Air wiring question

I'm in the middle of making up an endless air system with the denso compressor in my td5 defender.

I've got everything pretty much ready to go, but am stuck with exactly how to wire it up. The rest of the air con system has been removed for the sake of leg room, so I have one plug there (I'm guessing I'll have to tap into the correct wires for the switch?). I also have the pressure switch, which is just a standard ARB jobby off an old compressor.

Any clues on how exactly I'd wire this up would be great, thanks.


note: I know the denso compressor may or may not work for this. I have heard people say it will blow up in 5 minutes and others saying it will run for years. I've got an inline oiler on the suction so I guess I'll see how it goes.


I've attatched a few pictures showing how I've set it all up so far. Basically to save having to tap out the holes on the compressor, I've used the original fittings and had the new sections crimped on at the rubber part.

theres 2 types of switches a make to earth which only has one terminal and a 2 terminal type annoyingly they also come in normally cosed and normally open configurations.

grab a switch and a

in all cases the first part of your wiring goes

battery, fuse, (pole 30)relay terminals(pole 87(a), compressor, earth and you use the switched side of the relay to control the compressor,

the controlling side goes

switched ignition power, fuse(optionalish),control switch, (pole 85)Relay terminals(pole 86), compressor switch, earth

heres the fun bit...
if your pressure switch is normally open (which is unlikely) you need to either pull the main power from an existing heavy duty switched power feed or set up a reversing relay.

as for oiling it...

tap the breather line from the crank case ventilation to get the inlet air supply put the outlet of the compressor back onto the front mounted condenser and pickup the outlet air from the condenser via a moisture separating regulator like youve got in the picture.