What would the yellow to yellow wire be?
Would love to know what colour wires do what from the factory loom as well.

So I am certain the pump has failed which would make sense. I drove the car 1 hour when bringing it home. Stopped for half an hour to load up the spare engine. Drove about 50 Meters and the car stalled and wouldn't start on petrol again. Had to switch to LPG and get home on that instead.
Didn't try petrol again.

My car is running an aftermarket fuel tank because my LPG tank was in the factory position. Do you reckon they would have just used the factory fuel pump in the aftermarket tank? I stuffed my back today so I can't drop the tank to check!