These starter solenoids have been known to fail, and it might be smart to carry a spare. If you pull your starter cable and the starter motor does not engage, this could be the culprit. Assuming your battery and starter motor are good, bridge the two terminals on this solenoid and see if the starter engages. If a jumper wire or screwdriver to bridge the contacts makes the starter engage, than the guts of this thing have failed and a new one will fix the problem.
When replacing this switch, you may want to consider the cable, which we have here.
There is also a couple which links the two together, which is here.
There is also a little boot which covers the electrical cable connection, that is here.
