[JSeery]

You can use an ohm meter (ohm range on a voltmeter). An original type will show continuity between the battery post on the solenoid and the small starter terminal. If this is what you have, the battery connects to the battery terminal on the solenoid. The starter connects to the other large terminal, and the smaller starter terminal connects to a pushbutton on the dash. Pressing the button provides a ground to the solenoid, which energizes it.

The other style of solenoid will have continuity between the small terminal and the case of the solenoid. With this style the starter terminal connects to a pushbutton that provides power to energize the solenoid.