1992 Volvo 240 NO FIRE TO FUEL PUMP

I wanted to replace the external fuel pump myself. Expecting to relieve fuel pressure, I pulled the fuse while the vehicle was running, instead of the fuel pressure regulator (dummy)! The new fuel pump was installed, and fuse put back in, but now the pump won't cut on. Since then, I tried replacing the fuel pressure regulator, thinking it might have been stuck in an open position, but the pump still won't cut on. I later tried replacing the computer with a used one, but again, the fuel pump still won't cut on. Any ideas? Could the internal fuel pump now be giving trouble? I used my test light, and there's no fire to the fuel pump!