Have you got 2 powers on the 4 pin plug? There's a feed and earth each for the fuel sender and the pump. If you do have power then the pump looks like being the suspect
You could try wiring the pump directly to the battery to see if it turns. I've had it with a car where I had voltage at the pump, but it wouldn't work, it was down to the inability to supply current due to a corroded fitting.....worth a try?