What l remember is this truck is a little old by today's standards some were built with a powertrain protection system and some were put on aftermarket there was a small black box under the dash covers the wiring went to the main components that cause the engine to fail if something went wrong like low oil pressure or no oil or water problem like overheating it would shut down the spark and the horn would blow. Check to make sure that all your fluids are good and you do not have low oil pressure. if everything is good there could be a problem in the system. Might be able to disable it but l do not have wiring diagram..