I think its time to recap. Initially the difflock light was on only when the key was out. Everything else worked normally, and it went out when the LR was running.
Since then,it would not restart. I disconnected and charged the battery, and after that all manner of strange things happened. at one point the oil pressure and charge lights were on without the key, then that stopped happening. Now I have the difflock light on when the ignition is switched on plus the normal reds and the glow plug (timed). Every other electrical system seems to be functioning normally. When you try to start, nothing happens except that you can hear the starter relay click, but the solenoid does not operate. Reading the electrical library notes this indicates that the immobiliser ecu is working . This is confirmed by it doing all the appropriate tricks with lights and sounds when you press the correct button. I have read that the main feed to the solenoid is from the Main fuses (checked) via the yellow starter solenoid through the spider and on to the starter. Might this be the source, and can I check it out of the pouring rain.
Doug