What would cause a 1993 Spirit 3.0L V6 engine to seize after only running 5 min and not start again?

It depends... by Seize do you mean that the engine is locked up and wont turn at all. It could be a starter failure as if the starter went out or the Starter Solenoid causing the starter not to work or engage and by it not working or engaging it wont turn the engine over to start the vehicle... if it is turning over you have to check to see if your receiving fuel, then if you are, check for spark.