Onan 4BGEFA26100F

Having trouble with the starter relay. There are 4 posts on both the old and the new relay. Post 1 is the 12 volt input which is live at all times. Post 4 is the output to the starter. If you apply 12 volts to post 2 it engages the relay. My question is: where is the signal voltage that comes into the generator assembly. Surely it is not meant to piggy-back off that 3/8 inch positive connection going to the relay. A customer brought me this after he royally screwed it up. Nothing was hooked up. I think, looking at the wiring diagram that the relay is supposed to supply 12 volts to post 2 or 3 all the time, but there is no continuity there.

Here is a link to the manual. The diagram is all the way near the last pages.
http://www.cumminsonan.com/www/pdf/manuals/965-0528.pdf