Can anyone give some explanation on these regulator/rectifier observations

Hello,

I first posted my question in the 8th-gen-specific forum, without any luck for several days now. Maybe I should've posted right here to start with ? Sorry if I'm too insisting with my question, but this forum will most probably be more appropriate...

What I don't understand, is the interaction between the starter relay switch (closes when the starter switch is closed) and the regulator/rectifier (see also the scheme). Because when I remove the Main fuse (without ignition "on"), there is voltage on both sides of the fuse. 12,3V at the one side, 12,8V at the other side. I can only suppose the regulator/rectifier is supplying the 12,3V ? But then again, may I suppose that the regulator/rectifier doesn't really need the IGN signal to supply voltage? How does the regulator/rectifier react on its different input lines ?

If someone could explain what I've been observing, I would highly appreciate it

View attachment 80857

 

If the motor isn't running, the R/R isn't supplying any voltage. The voltage you're seeing with the ignition off
is from the battery. You may need to double check your methodology. If you pull the main fuse I don't
believe you should be seeing any voltage. That would indicate there is a backfeed from somewhere. JMO of course.