Hi Steady
had same problem recently with engine management light and glow plug light traced back to a faulty relay in seat box has been ok since. the only way i could get get the lights to come on before it was sorted was to have the ignition on the 2nd position then slap the side of the seat box with my right hand the ecu and glow plug lights would suddenly appear and i was then able to turn the motor over. hope this helps as i know how frustrating this is
Zak