[oneblueyedog]

I've lived with this plague for the past year and a half.

Checked voltages at the starter and battery- all great
I've replaced:
Battery 2 times.
Starter switch- PIA
Solenoid
Starter and solenoid
Cleaning all grounds-all of them
cleaned all the terminals-for the circuit-some were untouched from the factory, and green.
cleaned engine harness terminal plug.
Cussed.
Posts on the subject go over all of this. One dude ran an extra yellow wire directly to the starter. It solved it.

I start mine (an intermittent problem) by twisting the key multiple times
until it starts. Embarrassing.