1993 Chevrolet Caprice starter

If you think battery cables are faulty, replace them. The starter and solenoid are new? With the key off, the starter solenoid shouldn't click. The purple wire at starter solenoid s terminal should not be hot with the key off. If it is hot, either shorted to voltage, or ignition switch is faulty.

Check fusible links at battery junction block, under hood, passenger side, fender lining. One of the positive battery connections goes to the junction block. With fusible links there should be voltage coming and going from link. If voltage on one side of link and not the other, link is faulty.