[Billy-O]

What are we assuming before you started the restoration? Was everything working properly back then? And what's new besides solenoid and starter?

Finally, have you consulted a wiring diagram?

Be advise that you should have the proper starter solenoid. Some starter solenoids have two big lugs and one small lug. Sometimes the solenoids will have an extra small lug. The extra lug may for grounding like on a fiberglass boat..... Or sometimes the extra lug is a for a "hot"..... For example.... Such as lights that will go out temporarily so you use all the power necessary to start the tractor.