Steve replied:

With the sound coming from under the dash it could be a faulty immobiliser triggering the immobiliser relay, or it could be the fuel cut-off relay, which is also under the dash.

A comon cause for this is a dead or dying regulator producing low voltage or "dirty" voltage with lots of spikes. This could be the reason for turning off the headlights and the problem going away......less load on the regulator/regulator. It could also be bad connections producing spikes. Have an auto electrician give it a once over.

Hope this helps

Savvas replied:

I think you hit it on the head with lights. Getting your charging system checked out. My guess is that a diesel won't use as much electrical power as a petrol motor. Particularly an '82 vintage where engine management systems were largely non-existent. This could explain why the problem may be masked at certain times. A question that comes to mind is whether you experience this only when there are other electrical loads such as a fan or air conditioning being on during the day or lights on at night? If you drive around during the day with the air turned off, do you still experience the problem?

Bruce replied:

Peter, the problem is most likely caused by a faulty headlight rheostat. I had this problem a few years ago with the very same year vehicle. When I replaced the rheostat the problem went away. Good luck

Bruce replied:

Peter, Further to my last reply, that part is more commonly known as the Instrument Lights Dimmer Switch

Dave replied:

I had a similar problem in an 88 troopie.

We looked at all sorts of things, problem ended up being the cable from neg terminal to the chassis was dodgy, replaced the cable, problem disappeared.

Member - Jim replied:

You may as well have another thing to look at and that is the oil pressure switches. There are 2 senders for this, one which diplays oil pressure in the instrument panel and another which sends its info to the fuel system. Its this one which causes the engine stop solenoid to cut off the fuel pump.
If this persists and you need to keep going you can disconnect the control arm from solenoid to pump and continue driving, of course you must have confidence that is not low oil pressure and cause engine damage.
Replace the faulty sender and the problem should disappear.
Jim

Ray Hart replied:

Hi Peter, Had the same problem in a HJ47, Think it is to do with bad connections in the engine control system. Bugger to find ended up giving up. Since replaced the motor and problem has not re-occurred.
One quick way of getting around the problem is to remove the engine control rod. The rod between the engine control relay and the injector pump. Pull it up hard to remove it will pop off. The only thing is, you will have to stall the truck to stop the engine.
Temporary solution but it is much more relaxing driving without the engine cutting out all the time