Diesel P38 won't switch off

Has anyone else experienced this? I've only had the car a few months and was working through some of its mechanical issues when this happened. There is still power going to the stop solenoid with the ignition off. Suspicion is being cast on the ignition switch. Should the fuel lift pump still operate with the ignition off?
Does anyone have a wiring diagram for these, or would that be just too scary?

Look at the ignition relay. Cutout solenoid is driven from pin 3 on ECM. Fuel pump only runs when glow lamps are on, when engine is being cranked or with engine running.

Also do the standard check for signs/smells of burning in the under bonnet fuse box.

Thanks guys, very helpful. No burning smells so far, mind you I haven't finished fixing it yet so there's still a possibility!
All the engine-related relays (I can identify three yellow and one green) appear to be working. When the ignition is in II position neither the glow indicator or engine lamps on the dash show; they always did before this problem arose.
What's the likelihood the ignition switch itself is faulty? What part does the Becm play in all this, I've been reading the manual about it and met myself coming the other way
I'm off out into the elements, I'll be back when I next thaw out (didn't realize when I got this thing that a heated garage was essential)

BECM has a finger in all pies. But main relay for engine is relay 19. It supplies power to the ECM. ECM supplies power to fuel cut off solenoid. So i would think when ignition is off ECM is still powered. Still looks like relay 19 caput to me. Does it start now or is it dead?

Thanks Wammers.
I checked all the relays but will check this one again. What drives this one, the Becm or is it directly from the ignition switch?
We disconnected the battery (ignition on and off -ve terminal removed within 17 secs) and reseated all the accessible connectors on the Becm. When the battery was reconnected and the ignition turned on for the first time both the heater coils and engine dash lights came on as normal but the stop solenoid remained on when the ignition was turned off. Turning on the ignition a second time the heater coils and engine lights didn't come on.

Didn't attempt to start the engine since it's hard to stop! I'd put money on it firing first kick as it always has.

be carefull if it feeding from the turbo oil or sump it will rev its nuts off and then go BANG and you aint stopping it

wil2813 said:

be carefull if it feeding from the turbo oil or sump it will rev its nuts off and then go BANG and you aint stopping it

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Hadn't thought of that one. If I disconnect the stop solenoid on the injection pump it does stop but other things remain on. It does seem to be running on the right can of oil at least.

wammers said:

BECM has a finger in all pies. But main relay for engine is relay 19. It supplies power to the ECM. ECM supplies power to fuel cut off solenoid. So i would think when ignition is off ECM is still powered. Still looks like relay 19 caput to me. Does it start now or is it dead?

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We checked relay 19, this time swapping for another. This brought back my two favourite lights and appears to have sorted the stop issue. We tried starting it but now, after all the messing about, we have a battery issue so it wouldn't turn over. That's on charge, as are the two ace mechanics, the latter courtesy of John Smith. In the morning, once the battery is charged and we've sobered up a bit, we'll have a go at starting it. I'm confident that it will fire up and now that it's got a functioning relay in the right place I reckon it will stop as well

Thanks for the help, I'll let you know how things go (and stop!).

Freshly charged battery and the engine fired first time after the heater coil light went out.
Ran it for a few minutes then turned off the ignition. Still won't stop. A good slap on top of the engine fuse box stops it very reliably!
Swapped relay 19 for a different one but no change. Measured the voltage at the relay coil with ignition off to be about 6.5v we expected 0v.
Could it be a poor contact in the ignition switch allowing enough current to the relay coils for them to remain on until percussively reset?

Peasemould said:

Freshly charged battery and the engine fired first time after the heater coil light went out.
Ran it for a few minutes then turned off the ignition. Still won't stop. A good slap on top of the engine fuse box stops it very reliably!
Swapped relay 19 for a different one but no change. Measured the voltage at the relay coil with ignition off to be about 6.5v we expected 0v.
Could it be a poor contact in the ignition switch allowing enough current to the relay coils for them to remain on until percussively reset?

Click to expand...

If a slap on the fuse box stops it, why look at the ignition key? Your fuse box is fecked, a common problem. Take it out and take it apart, look for corrosion, burning, bad contacts that have heated up etc.

Good point, must have been thinking of a different bitch. I'll get in about the fusebox right now.

Well done and many thanks to all of you for your help. Special mentions to Wammers and Datatek who helped us focus on the real problem and prevented unwarranted adjustments to the innocent ignition switch.

The fusebox was removed and one of the connectors (purple) found to be corroded and full of water. This was cleaned with switch cleaner and a nylon brush, dried and the whole thing refitted. Now I can switch off the engine! With such an instant change of behaviour I reckon this was the cause.

We're off for a test drive, not too far from the beer of course.