Thread: ECU/ fuel pump relay/ fuse blown?

Hi, first of all if it's 3.9 it can't be D2 while if it's from 1999 it should be D2 but it can't be 3.9 eventually 4.0, that's just for accuracy

if it's D2 check if relay R9 closes on ignition cos this one feeds the pump relay's coil, the ECU is switching earth on the blue/purple wire not live ... the inertia switch must be on the bulkhead near the back of the engine you should find it or at least it's wires bridged cos the feed for the main relay(R9) goes through that circuit so investigate on that path

if it's a 3.9 D1 i have no ideea and you are in the wrong forum section then

Thanks heaps sierraferry I was thinking it was an earth but not too sure I'll hunt down that relay as it could be the problem.- So the other wire is the live, pretty certain its white and purple and there's two going in to the relay. I will have a hunt around this morning.

Originally Posted by timb2117

Hiya any help would be great, working on a disco 3.9, v8 circa 1999.

So as Sierrafery asked, is it 3.9l or 4.0l?

99 will be a D2 4.0
98 will be a D1 3.9

They are completely different.

You can't go any further unless you know which one it is.

The W/P wire is the output to the pump from the relay's contact

Originally Posted by shack

So as Sierrafery asked, is it 3.9l or 4.0l?

99 will be a D2 4.0
98 will be a D1 3.9

They are completely different.

You can't go any further unless you know which one it is.

Sorry I avoided that Q? reason being its actually the engine, loom and most ancillaries and LT77 gearbox in a Westfield, so a "seight", the build plate states '99 but there sadly is pretty well zero history on it and I suspect the engine was retro fitted later down the track, it has got a 3.9 plenum chamber.

Exactly what Sierraferry has said is correct and now I am over my "DOH!" moment I have reinstated the correct earth cutting feed from the ECU and it is working perfectly with an alternate feed for the live to the relay provided from a spare ignition terminal.

Thanks again to the forum I needed inspiration a good nights sleep and a strong coffee.