Do you have a WSM? You can download a free one here.
M108S WSM
I think you should take the time to rule out the most basic items. Battery cable, cable ends and cable ground to engine.
If you have a battery cable end that is like this one below, then buy a new cable if for no other reason than to eliminate it as the cause.
View attachment 61832
On page 425 of the WSM you will find the starter troubleshooting section which I have provided below.
View attachment 61833
I know you said power is not reaching the starter solenoid trigger terminal. Have you measure this with a volt meter. Sometimes tired safety switches put enough resistance into the circuit so that the starter solenoid is not triggered but a reduced voltage is actually reaching the solenoid.
Dave