Quote:

The draw is in the ~10ga wire that runs from the relay to the starter, not the 4ga (or whatever size it is) that runs right from the battery to the starter.



You shouldn't have any voltage to that wire unless the ignition switch is turned to "start". I would remove that wire from the relay and check for voltage at the wire and also where it connects to the relay. If you have any voltage at the disconnected wire then the starter would be the problem. If you have voltage at the relay where the wire connects then the problem might be the ignition switch or the relay itself.