Actually, I was wrong about what I said (just went out and did it myself).

If you cross the two posts, you'll be powering the starter motor, so you should hear the gear spin. If you give B+ to the signal wire, it should kick out and crank the engine over.

If you didn't get anything after crossing the two posts, then I'd pull the starter and bench test it.

 

I guess Autozone or Advance auto can test it for free....
They sell remanufactured one for 120 - 60 core

 

Problem Solved !

I took out the starter and brought it to Autozone; it was proclaimed dead
It was a pita to take the long bolt out. I broke a socket and an extention.

I paid $120 for a remanufactured Duralast with a lifetime warranty.

Put it in, and it starts like a champ.
Before replacing the starter I tried to swap all relays related to starting, cleaned battery terminals and grounds with no success.