If any temporary repair cable ends have been installed, start there and replace the cables with Ford parts. Load test the battery to rule that out, and check again for drains. The ignition requires very little current draw in a bump start, 8 or 9 volts will run the system but may not close the solenoid. There used to be a problem at the starter solenoid trigger wire, and replacement starters required a new terminal be installed. Most Ford issues involve cables/cable ends/ or battery posts. Universal ends are not adequate, acid migrates down the cable and makes a solder repair iffy and a good solder job still requires a mechanical crimp which most installers are unable to make. If your battery leaks acid, adding new cables is futile.