No power to fuel pump

I have gone through my owners manual for some troubleshooting ideas but have not come up with a specific diagnosis. I have a 1992 325i alpina that will turn over but will not start, we checked the fuel pump for power and it had none going to it,so we changed the dme and fuel pump relays and still no power, it broke down when I was driving in the rain so I thought maybe water in the fuel filter, but I don't know why the fuelpump wouldn't have power, so is this an electrical issuse or could it be the fuel filter or pump? I don't have much experience working on vehicles so any simple things I could check that would cause these problems as well would be appreciated!