1996 Volkswagen Golf Fuel Pump - Electrical

I have a 1996 vw golf that a friend gave me. The fuel pump is currently not engaging.
The way my friend described it to me is that he was on the highway when the car sputtered and died. He picked up a different fuel pump at a junkyard, but that one didn't work either.
I replaced the relay and the fuse - still not engaging the fuel pump.
I'm confused. I've pretty much concluded that there's no power getting to the fuel pump, and I'm guessing there's no power at the relay or fuse either.
How do I fix it, if my guesses are correct? Also, if the O2 sensor before the cat is missing, would that prevent power from getting to the pump?

Thanks,
Mike