I put the old starter on the bench. Negative jumper cable to bolt flange area starter for ground. Positive to top post on starter. Large screwdriver depressed on button. Nothing. Guess I need to try the new starter next. What a joke, who tests these and how often do these starters fail?
I always test them this way, when they show the symptoms that you posted.
No cost, and only a little time involved - also, if the starter behaves OK on the bench, if you clean/shine/copper-goop all re-connections (both the mounting surfaces, the bolts, and the cable ends), you probably will have solved your problem (bad grounds/connections).
