I have owned a few Case 1840 and 1845C sjidsteers. I currently have 4 of them. A common problem is not enough current from the ignition switch to the starter start terminal. The solution is to find the wire going to the starter under the seat. Cut it and install a solenoid switch or HD relay. Hook wire from Ign, that you cut, to energize the relay. Run a cable from battery power to one side of the relay and connect the wire from the starter, that you cut, to the other side of the relay. Problem solved!Case 1840 won't start unless I jump it changed battery still have to jump it to start. Changed the starter still have to jump it to start. Change ground cable nothing changed.