So... when you turn the key to "ON" you get everything on the cluster lighting up the correct way, but when you turn to "start" you get nothing?
If that is the case, it could be a mechanical problem at the starter or ignition switch, or it could be a problem in the wiring between the two. A common issue that causes this is neutral safety switch or the ignition switch lever being out of alignment. You can test the starter solenoid by making sure the truck is in park and emergency brake set with the ignition switch "off", take a wire and short from the big power lug to the small lug with a single wire on it. That should cause the starter to engage(but not start the engine because the ignition is "off"). If the starter engages, then you have an issue in the starter signal itself, which would point to a switch or wiring issue. If the starter doesn't engage, then you have a bad solenoid.