Had another go at this today. Fully charged battery New relay Swapped the entire front (race) loom for a brand new, never used one Took battery box off Took ecu out and cleaned all connectors, emeried the earth lead, nut,bolt and reconnected. Swapped the ignition aerial with my other one (known to be ok) Checked all wires around battery box and relay for signs of chaffing or damage - nothing found Rechecked all fuses, all ok Disconnected fuel pump and checked plug etc all ok Switched on and still no fuel pump prime. I can hear the relay clicking each time it is powered on. Error code 37.3 still. No amber light on dash, just a constant alternating of the “code” and temperature readout. I wiggled all wires while the power was on, behind battery, around ecu, at pump, into clocks, every-fuckin-where...dead as a dead thing. Arse.