Just guessing. But the grey wire is probably going back to the fuel pump. So that's pin 30. Across from that pin is 87.
85 and 86 trigger the relay coil. So. Touch the green wire on 85 or 86 to power and u should hear the relay click.
Or. If that grey wire is goin to the pump, just apply 12volts to it and the pump will power up. Obviously for testing purposes only.