Try checking all the wires in the wiring harness under the hood, could be a problem with a wire or a ground wire somewhere. Also check all of the ground wires under the hood (black wires) for any corrosion or tears. It could also be a problem with the engine control unit (ecu).
Try an ignition switch.
Starter Ignition Neutral switch
Sounds like starter solenoid needs to be replaced
Your neutral safety switch-try putting car in neutral and trying it
your ignition switch or the starter solenoid is bad try jumping the solenoid instead of the starter, if this does not work, then change solenoid
Which one?
the solenoid itself is probably bad, if not that probably the ignition switch I agree 100%, check the solenoid first then the switch.
The solenoid is built on the starter.
The starter solenoid, or ignition switch is bad, and either one needs to be replaced.
Yes
It is on the starter.
The shift solenoid is inside the transmission on the valve body.