Suggested wiring
As normal, the two engine alternators have negative connections via the engine body. Currently the leisure and starter batteries have their negatives linked and strapped to the engine body.
My issue is the BMV does not see the alternator charging the leisure batteries, so usually shows they're flat.
The solution I believe is to remove the link between the two batteries, so the leisure batteries are not connected to the engine body, but instead to the negative connector block the other side of the shunt. Thus alternator charging current will flow through the shunt.
See poor sketch diagrams.
Is this OK, or have I missed a vital detail ?