Okay, all breakers appear to function correctly - Power when ON, no
power when OFF. So I looked at the switch, and it looks like all
there might be two circuits connected together right then and there.
The box actually has two switches, which are on different circuits,
but the hots, neutrals, and grounds are bound together. I
disconnected them, took the switch out that controls my lights of
interest, and put it back together as it was, just with one switch
missing. now the lights have no power, nor is there voltage between
the hot and neutral of the wire that goes from the last light to the
switch that was removed. I see nowhere else where power might be
coming in from, as all there is now is the 4 lights with wires
connecting them. I'm guessing therefore that power came from the
switch and I've successfully disconnected it. Do you guys think I
should continue my search for what was going on here, or just be happy
that I accomplished my mission. E.g., is it truly a danger or fire-
hazard to leave as-is? Hasn't been an issue for the 10 years the
house has been standing. Thanks again.
I expect that it started out as or was intended to be two switches in
the box, each fed from a separate circuit (on the same leg by
coincidence) and each feeding separate sets of lights, but either the
new guy who installed the switches after the rough in, or someone later
got confused and thought the second feed was outbound, not inbound and
tied it to the other feed. If the OP has them separate now the problem
should be fixed.
Should be OK if you are sure that the switch box with the 2 circuits did
not have other wires going to other outlets and such.
You should now have 1 black hot wire going to a switch and a black wire
from the same switch going to a light.
The black hot wire from the 2nd circuit should be capped off with a
I would remove the 2nd switch and wire from the box but up to you.
IF you have any other wires tied to the hots in that switch box then you
could be EITHER overloading the one circuit while leaving nothing on the
OR you could still have a problem with 2 circuits tied together.
It seems that if that was original wiring then there would have been
more than 4 lights on a circuit. Maybe thats what confused the person
who did the switch box in the 1st place.
If it were me I would have just added the 4 lights to the 1st circuit.
I would separate the white neutral wires as well.
I've been shocked when working on a circuit where just the neutrals from
2 circuits were tied together.
Grounds are OK to be tied.
Also if it were my house I would go and map out every single circuit in
the house - one breaker on at a time.
If the OP shut every breaker in the panel (at the same time), and
there was still power, there is a big problem. Someone must have
wired directly to the main, or else there is a hidden panel somewhere.
Anyone that knows wiring would be able to trace that circuit back to
the panel. I always try to support people to DIY, but if the OP cant
trace the wires back to the panel, I suggest he call an electrician or
a friend who knows wiring. If that circuit is not on a breaker, it's
a fire hazzard. You dont connect a #12 or #14 wire to a 100A (or
more) main. An overload will set that wire ablaze in seconds. If
this was my house, I'd find the cause no matter what.
Maybe I am not understanding this, so here's the way to test.
I am assuming he shut off ALL the breakers at the same time. Then one
by one he needs to turn them on (only one at a time), and shut off the
last one that was turned on. In other words, only ONE breaker turned
on a a time. If TWO breakers made the same lights turn on, there
there is a crossed circuit (which is bad). If shutting off ALL the
small breakers (at once) does not turn off these lights at all, there
is an even bigger problem, as in unprotected circuit. Of course he
has to connect the light back to the switch or connect a meter or test
lamp to it. Working on a 10 year house should not be that bad. It's
not like some of those really old houses with the knob abd tube
A couple alligator clips on a bulb socket with a 25W bulb makes a
great tester. Costs under $5 to make one.
I'm a retired electrician. I've dealt with things like this, and it
needs to be fixed or can be very dangerous.
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