My '04 GV 2.8 diesel auto was running fine Saturday afternoon. Turned off for a few minutes and now won't turn over in 'P' or 'N'. Have tried charging the battery (7 hours on trickle charger), jump leads from another vehicle with engine running for an hour, disconnecting the negative lead for about 30 minutes, all to no avail. When I turn on, all dash lights are fine and extinguish as they should, wash/wipe works, heater fan ditto but when I turn the key the clock goes out and the heater fan drops speed. Makes no difference if I turn fan off. Before I get it towed to a garage does anyone have any bright ideas? Thinking gear position reader or starter? Any help gratefully received.