1994 GMC Suburban fuelpump relay

The relay shows to be located under the hood, on the firewall, a little left of center toward the passenger side.

Also if the datalink connector has a terminal G, if you run B+ to the terminal, the pump should run, use an inline fuse.

the orange wire is fusible link, hot all the time. Red wire goes to terminal G at the datalink connector, already talked about that. Gray wire carries voltage to pump when relay is energized. There is also an oil pressure switch in the fuel pump circuit, once you crank it enough to bring up oil pressure and the switch closes, the pump should run, regardless of the relay. The relay itself won't energize with out signal from computer, green wire, white tracer.