A:     Hi Jim. Your efforts seem concentrated on the ground cable. Did you try testing the positive cable? That cable is long, running to the starter under almost the full the length of the car. It is susceptible to corrosion and wear, but it still might be not be the problem.

Try putting a meter on the cable where it connects to the starter to ground and see if you have power there. If no power, the positive cable is probably at fault.

If there is power, the cable should be good. So next, try putting a jumper on the starter between the ignition switch connectors (the 2 small blade connectors on the solenoid).

If the starter turns over, the problem is likely in the ignition switch itself. The switch is itself is small device on the left side of the steering column/back side of the lock inside the plastic column cover. This is prone to mechanical wear and the casing loosening-up over time.

Once this happens, the contacts fail to connect and the car has no power. In the extreme, the plastic back cover comes off the metal case and the switch falls apart.

Replacement units are available from the catalogs, though these have one wire less than the original unit (I think it had been for the ignition lock-out from the seat belts), but it works.

I hope that helps you. Let me know how you make out. Good luck.

Art Isaacs