Ldv convoy no start( immob or ECU)

[Normalspeed]

Doing my head on this one.

2002 ldv convoy, suddenly gave no glow plug light on ignition & won't crank.
It's a duratoq 2.5L diesel.

Searched for immobilizer fuses - only one under ash tray found & seems good
Tested all relays(4 under ashtray( 2 dimmer & 2 supposed crank inhibit/ immobilizer)) + 7 by ECU(one supposedly fuel pump) - all click away. No relays whatsoever in engine bay - just 2 main fuses(50amp)
ECU was damp, the garage took it & sat it on a radiator over winter, but no visible damage or water getting into circuits

Wiring status unknown( cannot easily follow each wire)

Key guy says chip reader not working- so changed , but no affect(blue chip) so put the old one back on.

Have got a full wiring diagram now, but doesn't seem to match up to the terminals & fuses in the vehicle.

All forums point to 'wiring on the fuel pump'. If I could find the fuel pump, I could check this - checked fuel filter wiring though(just to be sure)

The crux of this - van has been down for 11 months now. All happened when a garage I hadn't used before did some welding & removed the passenger footwell panel.
They have now washed their hands, left van roadside to deteriorate with no mot.

Cannot read any fault codes(no communication from obd socket)(while booster attached to battery)
Imobiliser light flashes as normal(every 3-4 seconds, even when attempting to crank). Goes static just before battery dies.
No glow plug light
No crank
Only sound of one relay clicking on when turning ignition.

Any help would be good(even just a good location of where this fuel pump supposedly is).