guys, I was going to replace a dimmer switch when I ran across an unusual
wiring method in the single-gang receptacle box. The dimmer controls a
chandelier in the dining room, it's the only switch for the fixture.
Two runs of NM cable enter the box just like a typical switch. The two leads
on the old Lutron dimmer are connected to the white and black on the first
cable. Black on the second cable is connected to the *white*
on the first
cable but the white on second cable is capped off with a wire nut. When I
saw this mess I put the plate back on until I can understand it. The wiring
makes no sense to me unless the switch is placed at the end of the run and
the white on the first cable is being used as a hot, in which case it
should've been marked with some black tape. But then why is the black from
the second cable wired to the same nut (nut connects the black from second
cable, white from first cable, and the lead from dimmer) and why is the
white capped off? I can see several scenariors to explain this, none
The house is 35 years old and the whole subdivision supposedly had aluminum
wiring originally. All the wiring I've run across is copper so it's likely
that someone, sometime replaced all or most of the wiring...and who knows
how qualified that party was.
I'm thinking that I should (1) disconnect the black on the second cable (the
one with the disconnected white) and see if the dimmer and ceiling fixture
operate, then (2) determine if there is current in the black wire of the
second cable, then go from there.
Any thoughts on this wiring setup? Thanks!