Since the solenoid is basically an electromagnet coil, it usually does not matter which SMALL post the yellow wire attaches to. SO: The battery cable attaches to the large post closest to the front of the engine while the starter cable attaches to the other large post. Typically the yellow wire attaches to the small post closes to the center of the engine while the ground connect to the other and downward to one of the mounting bolts.
Now, there is a small red wire that also connects to the battery cable post. This supplies power to the ignition switch AND recharges the battery while the engine is running. If it is not attached, there will,be no power to the ignition switch.
The other small post on top of the solenoid must be attached to a good ground. Early solenoids were grounded through the mounting bracket and do not require a separate ground. Later solenoids are NOT grounded through the case and MUST have a separate ground.
The yellow wire travels back to the neutral interlock switch and then to the ignition switch. A broken wire here or a non connected one will prevent the engine from starting. SO will the misalignment of the switch and cam. The white button MUST be depressed in neutral.
