This can happen when power is going to the fuel pump relay. The relay wires are grounded on two wires. Electrical wiring issues can be a nightmare if you don’t have the appropriate wiring diagrams to see which wires goes where. If you have a multimeter, you can check the wire continuity from the pump and fuse block to the relay and all other associated wiring. A mechanic, such as one from Eurobahn BMW MINI Mercedes-Benz Audi, will help you diagnose the fuel pump’s loss of power.