From the Cub side of the forum, there was the following a long while ago...
You don't have to have a warning light, but you must have a lamp or diode between the no 1 terminal and the ignition switch. If you leave out the diode or lamp, the tractor will continue to run arter you cut off the ignition switch.
Is that maybe my problem? I don't seem to have lamp, and I don't know what a diode looks like...