When my starter switch started acting up it would work intermittently, sometimes only catching a contact briefly to make a click. I would wiggle the switch while pushing it in to try and get some contact going on, and it was then I could tell by the way it was behaving the switch was the problem. I did the starter switch maintenance cleaning, and it still acted up. I ended up having to take it apart again and stretch the spring that pushes up on the stunt strip to make the contact good and strong. Lubed it, too. That worked.
2008 Aero 750