Quote (OldAndyAndTheSea @ Jan 22 2014 08:54am)
That test is just a continuity test. Which actually tells a lot.
Unfortunately, it tells us what we already know. Which is that the ignition switch is fine, (I'm pretty sure somewhere the OP said the motor HAS cranked, intermittently, but doesn't start) so the continuity from the ignition switch to the starter solenoid, which is literally always just 1 wire, is fine.
If his battery does hold 12.5 volts on its own, there really can be culprit: the solenoid itself.
OP: if for some reason I am incorrect in my assumptions, I would recommend checking the ignition switch, just to eliminate the possibility. But again, I'm pretty sure your starter is at fault.
Some ignition switches can fail intermittently as well, because they have physical contacts inside of them and they build up carbon tracing. Every once in a while they will make good contact and start. You are right though, 99% chance starter/solenoid is faulty here, but if you are going to replace the starter you might as well check for power at the S terminal.