Slowcrash_101

You have a huge voltage drop, something in the cable is corroded or partly broken. You should show less than .5 volts while cranking.

daeven

I decided to bypass the 0 gauge wire (or whatever size it is) to the starter in an attempt to prove the starter is good. I had a section of wire from an amplifier install on another car, and was about to hook it up. I started by removing the negative battery connection, and then looked over the positive wire. The PO had replaced the positive terminal with an aftermarket contraption and apparently modified the connection for the starter wire. There was a second screw-type connection for the starter wire, and sure enough it was loose! I popped the wire out to see plenty of indication that it was a bad connection for a while. I cleaned it up and reattached everything, and all is good now.

Thanks for saving me from replacing the starter again!