That’s not a lot of information to go off of. My experience with classics of that year, there is a solenoid mounted on the drivers side left upper corner (outside firewall). It is a relay between your start button and the starter solenoid. You could check there.
None of our trucks 2001 to 2016’s have ever had a neutral safety, not saying your truck doesn’t have one, just saying theres a chance it doesn’t.