[ossiblue]

The posters above have you on the right track.

One of the key diagnostic signals is the "click" referred to by T77911S . If you don't hear it, the likely suspect is the switch itself. Listen carefully for it (maybe even have someone else turn the key while you are outside the car) and also note any dimming of lights (easier to detect in the dark, of course). No click and no dimming points to the switch--no flow of current. Dimming of lights points to the solenoid/starter as current is flowing but is impeded.