I attached the relay schematic below. First, in the engine compartment fuse box, fuse 13 provides power at all times to the relay. That power reaches the relay's primary side via a red wire. For power from the red wire to flow through the relay, there is a light blue wire with an orange tracer. That provides a ground path by the PCM to complete the primary side of the relay circuit. This causes an electromagnet in the relay to close the power supply portion on the secondary side of the relay sending power from fuse 9 to the pump.
So, here is where I would start. First, remove the PCM power relay and make sure there is no corrosion or any issues in the box and that the relay itself is good. If that relay doesn't close, you get no power to the fuel pump relay and fuel injectors which would explain why running power directly to the pump with it running, the truck still wouldn't start.
Actually, to make that test easier, check the red wire at each injector to see if there is power with the key in the run position. Do that and let me know what you find.
Also, try switching the relays with others having the same part number. If there are none, here is a link that explains how to test one:
See pic below.
Monday, February 27th, 2023 AT 6:27 PM