1996 300tdi fuel stop solenoid power issue

Engine cranks over perfectly. Solenoid works everytime when direct fed from battery and engine starts every time. Fault traced to: no voltage from wire on solenoid. No fuses blown. Does anyone have a copy of the wiring diagram so I can trace the black wire at the fuel solenoid back? Just discovered it runs via the immobiliser. I'm thinking I just run a new feed from ignition switch. Anyone know what colour wire from ignition switch ?

Have you checked the fuel inertia switch

I was not aware that a Discovery 1 had an inertia switch.

Stanleysteamer said:

I was not aware that a Discovery 1 had an inertia switch.

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The ones with a petrol engine do, thats because they have an electric fuel pump.

Jason F said:

Engine cranks over perfectly. Solenoid works everytime when direct fed from battery and engine starts every time. Fault traced to: no voltage from wire on solenoid. No fuses blown. Does anyone have a copy of the wiring diagram so I can trace the black wire at the fuel solenoid back? Just discovered it runs via the immobiliser. I'm thinking I just run a new feed from ignition switch. Anyone know what colour wire from ignition switch ?

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Yellow, it can be found along with a white and white/red wire, the three wires are in a black sleeve and can be seen plugged into the r/h side of fuse board, so tee your link wire there, and then via a grommet near the throttle cable into the eng. bay, follow the existing loom to the solenoid, a bit of mechanical protection with a length of sleeving to suit is alway handy.

I did a similar thing around 10 years ago, but that wire went to the ignition coil, when that part of the immobiliser failed on my D1.

discool said:

The ones with a petrol engine do, thats because they have an electric fuel pump.

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Fur enuff.
So his 300tdi doesn't then.

Diagrams here https://docdro.id/V5IMQLk

Thanks Discool and others. I see the 3 wires plug exactly as you say. I'm guessing the yellow wire is energised when the ignition is on. Thus, I can take a feed off the yellow wire and run it to the cut-off solenoid by the sound of it. I'll look at doing this (and add an in-line fuse). Interestingly I have discovered that if I use the remote fob and lock/unlock 3 times, the power to the cut off solenoid is re-instated. So I'm going to see how that goes for a while.

discool said:

Yellow, it can be found along with a white and white/red wire, the three wires are in a black sleeve and can be seen plugged into the r/h side of fuse board, so tee your link wire there, and then via a grommet near the throttle cable into the eng. bay, follow the existing loom to the solenoid, a bit of mechanical protection with a length of sleeving to suit is alway handy.

I did a similar thing around 10 years ago, but that wire went to the ignition coil, when that part of the immobiliser failed on my D1.

Click to expand...

sierrafery said:

Diagrams here https://docdro.id/V5IMQLk

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Thank you.

Jason F said:

Thanks Discool and others. I see the 3 wires plug exactly as you say. I'm guessing the yellow wire is energised when the ignition is on. Thus, I can take a feed off the yellow wire and run it to the cut-off solenoid by the sound of it. I'll look at doing this (and add an in-line fuse). Interestingly I have discovered that if I use the remote fob and lock/unlock 3 times, the power to the cut off solenoid is re-instated. So I'm going to see how that goes for a while.

Click to expand...

The locking/unlocking several times is a early indication of that immobiliser circuit is intermittently failing to remobilise the engine, the number of fob presses of the unlock button is not specific it can be more, even leaving and returning a short time later could work, its the unlock function that carries out the remobilise function.

Eventually this immobiliser circuit will fail fully, including the part that recognises the fob being present at the ignition switch, and thats at any time, like it did at 50mph with my D1 on the 3rd lane on a busy A road

Hi discool, I bypassed the immobiliser and now run the fuel solenoid from the ignition switch. So that issue is fixed. My immobiliser fob locks operates as it should, every time reliably. However, now when I push fob button, all doors lock, then a second later all doors unlock. Can anyone explain what could be causing the immobiliser to immediately unlock the doors again? All the door light switches function fine.

Might be problem with the inertia switch, on the 300tdi seems that you can't do much about it cos it's incorporated in the alarm unit not on the bulkhead like on petrols or Td5

from the WSM:
Inertia Switch
An inertia switch is incorporated in the Theft Alarm
Unit (Z163). If ignition is on and the vehicle receives
an impact sufficient to activate the inertia switch, the
unit will signal to unlock central locking actuators and
flash hazard lights.

sierrafery said:

Might be problem with the inertia switch, on the 300tdi seems that you can't do much about it cos it's incorporated in the alarm unit not on the bulkhead like on petrols or Td5

from the WSM:
Inertia Switch
An inertia switch is incorporated in the Theft Alarm
Unit (Z163). If ignition is on and the vehicle receives
an impact sufficient to activate the inertia switch, the
unit will signal to unlock central locking actuators and
flash hazard lights.

Click to expand...

So nothing to do with engine fuel system, thats cleared that up then.

Jason F said:

Hi discool, I bypassed the immobiliser and now run the fuel solenoid from the ignition switch. So that issue is fixed. My immobiliser fob locks operates as it should, every time reliably. However, now when I push fob button, all doors lock, then a second later all doors unlock. Can anyone explain what could be causing the immobiliser to immediately unlock the doors again? All the door light switches function fine.

Click to expand...

Bounce back it the term used by LR in my RR days. Its a result of the drivers door lock actuator being out of adjustment, only slightly but enough that the actuator doesn’t move fully.

Basically, its release the 4 screws securing the actuator mountain plate and move it left or right very slightly till the lock - locks unlocks - using the fob as it should, then tighten the screws.

its a central locking issue nothing to do with the immobiliser .