92 PA intermittent starting problem

Hi everyone,
I'm new to the forum and have a problem with intermittent starting. 92 PA only 68k miles. Had security system bypassed, new interstate battery. The car will start most times and runs great but once a week or so she won't crank. All the system lights come on and doors and windows get power but car will not even try to turn over. I can wait 15 min. and it will crank most times. Could someone please help. TIA

Welcome to AF! When you changed the battery, did you also remove the terminal insulation and clean all the terminals and the spacer in between? Can you jump the starter from the positive battery to the starter solenoid purple wire? Have you checked the gear selector switch? I hate to answer a question with more questions, but sometimes it is necessary to find a resolution.