Also, a solenoid is hard to diagnose because of you hear a click, it is closing that connection and pretends it's okay. It bridges the terminal and gives continuity on an ohm meter, however it has been my experience that while it may pass voltage, it might not pass enough current. That happened in my dad's mercruiser once. The only thing that suggested the solenoid wasn't giving enough current was a slight voltage drop on the activated pole with the starter disconnected (like .1V or something).