Wont Turn over

Hi Hitch2, Welcome to 2carpros

Get the alternator and battery load tested if okay make sure its clean and properly connected-Test the fusible links-still no crank your possibilities here could be one of the following it sounds like the starter has gone out but to be sure lets run down this guide.

https://www.2carpros.com/articles/starter-not-working-repair

The starter, starter relay/inhibitor, park and neutral switch and ignition switch assuming the battery and connections are good

Try this link to reset the security

https://www.2carpros.com/articles/how-to-reset-a-security-system

If your saying the starter motor won't crank, I don't believe the security system has anything to do with starter motor, it should crank regardless, In my opinion.

If starter motor won't crank, have to check voltage and ground circuits for starter motor. Any testing at starter motor, make sure tranny is in park or neutral and functional parking brake is set. You don't want the vehicle to move when testing. Safety is your responsibility.
If any of my colleagues say the security system will disable the starter motor, then I stand corrected. Have a good day.

Next time it refuses to start-do below immediately to determine if it's fuel or spark issue:

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it