For a quick test of the starter:
- disconnect the small-gage wire that connects to the starter solenoid-terminal;
- connect a wire to the positive battery terminal; and touch the other end of the wire briefly to the starter-solenoid terminal.
This will put 12V to the solenoid, and should energize the starter itself. But be aware that the test-wire from the battery will be unfused, and capable of conducting a larger than intended current.