The truck was dying sometimes. We changed the fuel pump out and now the new pump will not kick on. We spliced the wires and installed the new connector just like the paperwork showed, but it will not kick on. I checked the fuel pump relay in the fuse panel under the hood. Is there a shut off somewhere else that might have tripped out while we were changing it.

Did you check for spark? ignition coil? Wiring /connections?injectors firing?

You definitely have wires crossed. I would undo your splices one at a time until the lights go of and the alternator stops it's thing. Then check the wire colors again closely

The splice would be outside of the tank. If you spend a little more money at the dealer you won't have to splice it.

Those rattly noises are detonations,  caused by a very lean mixture. All the other symptoms indicate that the fuel flow to the carb is too low. Since you have replaced the pump and the filter, the only other things left to check are the lines and the tank sump. Or you could install a much larger pump.

Not sugestable

Do this :
Turn the key forward and listen for the fuel pump to pressurize it will make a high pitch sound. If you do not here if then the fuel pump is not kicking on. Might need two people to do this, one to turn the key while the other one listens for the pump to kick on. It could be the fuel pump relay switch witch should be a green plug and the drivers side seat or behind the kick panel on passenger side floor board where your right foot would be. Also check for a fuel pump shut off switch on the same side. Push button down if equip with fuel shut off switch.

change the crank sensor before anything else.That sounds like your problem.

Find power wire coming from relay to pump when key switched on, & follow it back to pump. If you have power out of relay & nothing at pump, then I'd look for a break in wire to rear, or just run a new one. Double check your ground as well.

since changing the pump makes a difference even for a short time, I believe you are on the right track with that. What you need to do is determine why after changing the pump the problem re-appears. What you need to do is check the fuel pressure at the throttle body, comparing "new" pressure to pressure from a non-working pump. You also need to check voltage at the pump to see if it changes. It may help to put an additional ground wire spliced into the existing one back at the pump harness...a poor ground will cause the pump to overheat and fail. I assume that when you changed the pump you completely drained the tank and cleaned it out so there is no issue there? Changing the pump will not change the operation of engine controls so I don't see a connection there. Pressure regulator may be an issue, but most fail to the "rich" side and you would know that right away...changing the pump would actually make that worse, not better. So, that leaves testing to find out the why of it.

check for a bad or missing ground at the pump