I am not aware of an OP Manual that covers Onan powered tractors built after the serial number spread shown in 9-9930. As you probably know, the Eastman site has nothing to offer, either. No surprises there.
First off, the solenoid doesn't care which wire you connect to which small terminal. The solenoid is not "polarity sensitive". You are correct that the solenoid receives power from the START terminal on the ignition switch and that the other small terminal on the solenoid heads to the PTO safety switch and then to the Neutral Safety Switch under the travel lever. However, your tractor might also have an "Operator Presence Switch".. aka "seat switch" that will not allow the engine to start unless an operator of a certain minimum weight is sitting in the seat.
If the condition of the solenoid is in question, then connect the yellow lead coming from the ignition switch to the solenoid's small terminal and then run a temporary wire from the other small terminal to battery ground. Turn the key to start and the engine should spin over.
If you then remove the temporary wire, connect the loose yellow wire to the solenoid and find that the engine does not spin, then you have a safety switch issue that needs to be diagnosed.
First off, the solenoid doesn't care which wire you connect to which small terminal. The solenoid is not "polarity sensitive". You are correct that the solenoid receives power from the START terminal on the ignition switch and that the other small terminal on the solenoid heads to the PTO safety switch and then to the Neutral Safety Switch under the travel lever. However, your tractor might also have an "Operator Presence Switch".. aka "seat switch" that will not allow the engine to start unless an operator of a certain minimum weight is sitting in the seat.
If the condition of the solenoid is in question, then connect the yellow lead coming from the ignition switch to the solenoid's small terminal and then run a temporary wire from the other small terminal to battery ground. Turn the key to start and the engine should spin over.
If you then remove the temporary wire, connect the loose yellow wire to the solenoid and find that the engine does not spin, then you have a safety switch issue that needs to be diagnosed.