OK, carrying on from the previous on extending circuits; have pulled to
the new junction box location--wasn't bad; actually less trouble than I
had expected and had ample cable length on the shortest without
scrimping inside the junction box.

OK, then I had another bright idea -- the dining room is the one with
the four entrance/exit points but only three switches--while not going
to even attempt to get the fourth location, it seemed like a nice
amenity to add a second on the east entrance at the dining room wall
itself instead of all the way to the exterior door.

The power is fed to the 3-way switch that was at that location (exterior
door/wall) with three wire cable running whither I cannot discern
precisely. Opening the boxes, the 4-way is on N door, the other 3-way
on the W. I made the hope that the 3-way cable went next to the 4-way
so put the two travelers between the existing 3-way and a new 4-way and
connected the 3-way cable travelers to the other side of the 4-way...

Unfortunately, that apparently is not the actual path as the new 4-way
now acts as straight on-off: in one position all other locations work
as normal; in other position none work.

I've got some other support work to keep the construction crews moving
I've got to go do so haven't been able to scratch head over this --
anybody here got time to ponder this out and see if can deduce how must
be wired and if I can manage to make this work without having to tear
into interior walls?

If I can't make this work, I'll just live with the location either being
where it was, or, perhaps even better thought, can remove the dining
room control from the exterior door location entirely and reduce the
number there...that may be even better overall solution since there will
be control of the entryway at that same new location so won't have to
backtrack to turn it off on coming home as did which is why the DR
switch needed to be clear out on the exterior door...otherwise you
turned yourself back into a dark house or had to walk back the door to
turn that one off because it was only location for it.

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