p38 alternator fault

P38 dse alternator fault message came on and after about 10 mile and a couple of stop starts of engine in between the engine just died. Would not restart but had loads of battery power. Eventually started with a jump. Turned off and tried again without a jump, no joy. Would a duff alternator cause the engine to shut down or is there something else. Funny it starts from a jump. Any input would help. Thanks in advance

I guess without replenishing the battery the power just runs out. Diesels need a strong battery as the compression is very high. Check out your alternator output with a multimeter. The fact you can jump start suggests no other issues.
Jb

Check battery output as well. 12.6v (upto14.4 v off the alternator to charge)

Put a volt meter across the battery terminals and see how much the voltage drops when starter engaged. then chech earth terminal.

Rangerover.net has a very good electrical troubleshooting guide. After that you could take the battery off, charge it and then see how it holds charge over the next few days. You can get the gubbins with the voltage regulator and brushes for about a tenner with the bonus that it has the higher set point of 14.5V for modern batteries.

Thanks for all the input. The battery had loads left when the engine cut out so why would it just cut out as a doosil dont need power to run. Or does it on a 38

Tony e said:

Thanks for all the input. The battery had loads left when the engine cut out so why would it just cut out as a doosil dont need power to run. Or does it on a 38

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The P38 needs LOADS of electrical oomph to keep the thing going....whilst a diesel in primative form requires nothing more than heat, compression, fuel and air to run, on a modern Diesel engine (the P38 included) requires electrical input to regulate the pump, read the sensors for optimal performance output, etc etc....if there is no power, the solenoid in the pump will close...or of the ECU isn't getting healthy power, it will shutdown, and turn off the engine.

Tony e said:

Thanks for all the input. The battery had loads left when the engine cut out so why would it just cut out as a doosil dont need power to run. Or does it on a 38

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If there was loads left in it and it was turning over then I think it might be an earth connection somewhere. Diag might help. ALTERNATOR FAULT is usually what it says it is. It is possible the diodes might have gone in which case charge might have gone back the wrong way. That would cause the message, might mess a sensor somewhere and for a while the battery would be OK. However, the battery might be receiving AC instead of DC or might be getting nothing.

Lift pump relay is pulled directly by + from alternator when engine is running. If alternator fails lift pump will die. If lift pump is genuine with NRV the injection pump may not be able to draw fuel past it at low RPMs. Hence the stall.

Thanks again to one and all. Recon alternator fitted. Peace and harmony again wondered what was going on. All clear now. Thanks

Well, it was bleeding obvious considering it told you 'Alternator Fault' on the message display.....it ain't there for sh!ts and giggles yer know

Ye but, i know but, it stopped an started but. an tricked me

Grrrrrr said:

Rangerover.net has a very good electrical troubleshooting guide. After that you could take the battery off, charge it and then see how it holds charge over the next few days. You can get the gubbins with the voltage regulator and brushes for about a tenner with the bonus that it has the higher set point of 14.5V for modern batteries.

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I replaced mine with item number 331890090841 off the bay,set point of 14.7, a tad over a tenner you cheapskate

Tony e said:

Ye but, i know but, it stopped an started but. an tricked me

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They do that. Keeps you on your toes!

Get a life get a P38. Motto.
Thanks Wammers and Datatek for inputs.

Got the " alternator fault" message again, new alternator fitted, much smoother, and remarkable reduction in fuel consumption, would never have thought it would make that much difference ! Getting better than 10 l/100 heding on to 9.2: