Have you tried to jumper across the positive cable to the starter cable on the solenoid? If the starter turns doing that, then you have problems in the wiring to the solenoid. Remove the small wire on the solinoid and use a screwdriver or slip joint plier handles and jumper to the positive cable( be careful will arc and burn things in two if not held on to the posts firmly) This should activate the starter, if not and the other test does, you have a problem from the start switch to the solenoid