Ford Fiesta 1.4tdci cut out when driving won’t restart

[Tarara]

Hi I have a 2005 fiesta 1.4tdci had him 10 years never had a problem until a few days ago. 
started up no problem drove about 200yards and just cut out. Wouldn’t restart. No lights on dashboard, no trying to start up, just dead. 
the only things working are central locking, lights and immobiliser light is flashing, not rapid flashing. 
breakdown came out, tried jump starting, nothing. Checked battery output said was normal range. visually checked fuses said all ok, thinks it’s immobiliser so is booked in at main dealer for next week, breakdown recovering to there as well as taking me back home as was so close. 
but any ideas of anything else it could be to try in meantime? 
thanks in advance for any help

[dezwez]

timing belt maybe

[Zen23]

Fuses. Immobiliser or ecu fuse could be 

[DaveT70]

Try the alternator connection. Or the alternator itself

When you say "NO LIGHTS" did you mean no ignition lights?