D3 compressor relay won't bridge

[dubzilla72]

Hi guys,

I currently have a suspension issue on my '05 D3. The car is on bump stops with red suspension fault light.
I originally thought it was my compressor failing. After pulling my compressor out, cleaning it out and checking it over, I've tested it direct on 12v and it seems to be running fine. Chucked it back in, changed over the relay but it still wont run when the car is on.
I took my old relay, popped the cover off and bridged it while on the car and the compressor will run successfully. So I'm at the point now where I figure the car isn't telling the compressor to run for some reason.
Does anyone have any knowledge of what causes this? I don't currently have a fault code reader for the Discovery, looking to pick one up soon when I have the funds for it.

[PerthDisco]

Definitely replace relay and main big fuse in older cars. Can get same relay from Repco. It’s the cheapest place to start.

Check the smaller fuses also following the legend under fuse box lid of the car symbol. There’s even a fuse behind the glove box also to check.

[BradC]

The relay is driven directly by the EAS computer. It supplies both sides of the coil.

Engine bay fuses :
Fuse 3E allows the computer to monitor the supply voltage to the compressor post-relay.
Fuse 26E is the battery feed to the EAS computer.

CJB fuses :
Fuse 35P is the ignition signal to the EAS computer.

In general my experience is the EAS won't fire up the compressor unless the CAN bus says the engine is running.

Unfortunately to go much further you really need the fault codes.

[crawal]

I have the same problem auto sparky can bridge the relay , where is the earth from the compressor?

thanks

[PerthDisco]

I have the same problem auto sparky can bridge the relay , where is the earth from the compressor?

thanks

I think it is behind the wheel arch liner on passenger side.