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94 Disc 3.9 fuel pump circuit

Don NZ

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RHD 3.9 pre face lift

Gidday Folks

I've got no power to the fuel pump circuit.

Do you know the location of the fuel pump relay, if above the drivers pedal which relay, and what colour wire run to it ?

I've located the black inertia switch mounted above the clutch pedal one whire white one wire white/ purple. no power to either

From the ecu faulty findiong jpg I've noted pin 16 turns the relay on.

from my experience white is usually unfused ignition so I suspect the inertia switch may be on the power side of the the relay coil and the ecu on the ground side.

I appreciate your thoughts

Regards Don (In the middle of winter !! )

p.s. great job on the cricket !!

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Gidday Again

Disco lives !! main relay was faulty ( winding open circuit) located above clutch pedal along with the fuel relay.

main relay not powering up so ECU woudn't ground fuel pump relay so no injectors or fuel pump.

relay a little small for job asked of it, I've replaced it with a higher spec unit ( bosch diode protected 75A)

here are my notes, may help the next bloke trying to sort !

1994 3.9 efi Discovery non flap airflow meter ( AM 5) ecu mounted rh kick panel

Main relay mounted above clutch pedal not in footwell !

Brown 30, Brown / orange 87, brown 86, blue/red 85

Bosch NO (normally open) relay diode in series with winding supplies power to the ecu.

It is grounded by the ECU with key on at pin 12 thin blue / red.

This in turn allows ECU to ground Fuel relay also located above clutch pedal

identical Bosch NO relay

Brown 30, white/orange, 2x white/purple 87, blue/red 85,white/red 86

to turn on via pin 16 also different thin blue/red.

inertia switch black assy above clutch pedal

plunger on top, down = on up= off

2 wires white and white/purple powers up with fuel pump relay.

Regards Don

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