Are you familiar with wiring schematics? Everything you need to know is in the schematic. It shows you where the relay gets its power from, what connectors are involved in the circuit. It shows you what controls the relay.
I would be checking the fuse block terminals for the fuel pump relay for the correct voltages. If you look at the small schematic on the relay, it shows you 4 or 5 circuits.
Curcuits 85 and 86 control the coil to the relay. Circuits 87 and 30 are the supply for the fuel pump. For the relay to work, the relay control circuits need to have a power and a ground. The pcm supplies the ground, so with the ignition on and the engine cranking, you should be able to get a test light to light if you put one end on 85 and the other end on 86.
If the test lamp lights, and the relay clicks, then you need to make sure you have voltage available at the fuel pump relay fuse in the fuse block under the hood. It should be very close to the fuel pump relay itself. Check for voltage at the fuse.
If you have voltage at the fuse, and the relay clicks, and you still have no power getting back to the gray wire at the fuel pump, then you have a broken wire between the fuse block under the hood, and the fuel pump.
I can't be more specific than that. Electrical problems like this sound they would be simple to fix and find, but they involve some detective work.
Let me know what you find out.
I'm here to help. You just need to let me know what you need help with.