Ford CMP horn wiring

[david moore]

I have a couple of electrical/wiring questions re my F8 Cab 12.
The horn (original) has only one wiring terminal. I believe that this should connect to a solenoid ( or relay - same thing?) that is itself connected to the battery. The horn button grounds and activates the solenoid such that current flows to the horn. Right?
The wiring diagram in the manual shows the horn wired via the starter solenoid but surely this can't be right? Can that solenoid provide two diffferent functions independantly? Mac's Auto sells horn relays- so is this what I need? No mention of such on the wiring diagram. How does the horn operating current get grounded?

Two questions re the starter solenoid itself. Is the small terminal on the side the connection to the starter button on the dash?
Finally, I'm using two batteries- a 12V just for the starter via the starter solenoid - it makes starting so much easier - and 6V for the rest. I know that the starter motor can take 12V if used sparingly - which is the case since it starts first pull on 12V - but is the solenoid ( meant for 6V) OK for use with
12V?

Cheers
David Moore
Kingston