On Mon, 20 May 2019 11:47:08 -0700 (PDT), wrote:

I think the OP was asking a simple question about powering the 12 v clutch using the 6 volt supply from the tractor AND a 6 volt battery in SERIES.

YES, that will work fine.

If you want to get fancy you can hook up a DPDT switch so the 6 V battery is charged by the tractor when the battery is not being used to power the clutch.

mark
Actually I was thinking of using the tractor generator is series with
the existing tractor battey, not an extra battery.
Eric