B+ battery power comes through the key switch, fuses and relays.
The relays close to provide power from a signal in the computer, in trucks made after 2004.
Usually the fuel relay does not energize because some other sensor has not worked properly and the computer (properly) shuts off (or never turns on) power to allow flow in the fuel system.
my bet, on this truck, is the crankshaft sensor, but could be a few others, including the cam shaft sensor or the O2 sensor.