Not sure I understand that last sentence.
On older cars, and especially trucks, it's not uncommon for fuses to be good but they don't work because of corrosion. Just remove and clean them with abrasive cloth. Apply a light coating of dielectric grease or spray with WD-40. The key fuses to focus on are #13 (Starter Signal Fuse) and the ACG (ALT) (S). Fuse 13 controls power to main relay Terminal 6, the second relay within the main relay. Did you depress the clutch when you tested Fuse 13? The ACG (ALT) (S) fuse control power to the first relay (Terminal 5) within the main relay.