It was simple!
A stray earth wire (the same colour as the glow plugs wiring) was touching the glowplug near the radiator.
NRMA must have hooked it on.
I disconnected it, and it started after a 20 sec glow. It's cold in the mornings up here!
I've no idea what that earth is doing. I'll tape it up later today.
thanks folks!
Alastair

