[Second Series]

That sounds right. On a typical set up the battery would be connected to that big terminal. If you had a problem with the starter not working, and suspected the key switch, you could put a screwdriver across the big and small terminal to see if the starter spins. You'll need to energize the small terminal, so yes, put a jumper. Years ago a friend had a mustang that would sometimes fail to stop starting, turn the key to start, starts, release the key, starter motor continues to spin. Every time was a frantic race to get the battery disconnected. If I knew then what I know now...Could be the starter solenoid was not releasing.