What I have done to check the fuel pump is connect two wires from the battery to the pump the pump then works. If I put the original wiring back on the fuel pump it does not work, and does not pump fuel this is why I thought it was a wiring problem or relay problem, not had an Omega before. I know its a fuel problem because I had the pump working with direct wires from the battery to it, the car then runs. Once I have got it running its works for a couple of days then gives up again, its like it has some kind of loose connection.