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Discussion Starter · #1 ·
Can you help me understand what's going on with this wiring?
I have a two gang box, and only interested in understanding the left side of it.
The left side is for a switch that controls an outside front porch light.
It's got 4 Romex 2 coming into it, I think, but correct me if I'm wrong on that.
Four lines that each have a black/white/ground wire.
The ground wires of the four are all connected.
The two sets of wires on the left two Romex are disconnected, except for the ground.
The two sets of wires on the right have the whites connected, and the blacks connected with another black also coming off of that, which is disconnected.

Attached is a pic or two to try to show that.

Why would there be 4 Romex coming into this one switch?
And how to wire those 5 disconnected wires to a basic light switch to handle the porch light?
Where would those 4 Romex sets be going?

Circuit component Electrical wiring Gas Cable Wire


Wood Electrical wiring Gas Cable Circuit component
 

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OK, we need to get some common terminology, I can't really understand what you're describing since the switch appears to have been removed. Wire denotes an individual conductor, often in an insulated jacket. Cable is a bundle of wires with an additional sheath holding them together. Romex is a brand of cable. So, can you clarify these statements:
"The two sets of wires on the left two Romex are disconnected, except for the ground.
The two sets of wires on the right have the whites connected, and the blacks connected with another black also coming off of that, which is disconnected. "

Or, have I missed the whole point and you're asking about the switch we're seeing in the picture?
 

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Discussion Starter · #3 ·
I'm trying to understand how to wire the left side of that 2-gang box to a single light.
The switch that is still wired on the right side of that 2-gang box - it's all good.

On the left side of that 2-gang box, there are 4 cables coming in, each with a black/white/ground wire.
 

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Discussion Starter · #5 ·
Did you remove a switch from the left side? Did the porch light work before? If there was a switch there, did any other lights work from the same switch?
I did.
And it did.
And nothing else that I know of dependent on that switch being connected.
But that gives me something to check... I spent a day a year ago figuring out which circuits go to which switches/receptacles/appliances.
So it maybe makes sense to figure out which of those are no longer working if the connection is broken here.
 

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There may be receptacles that are not working, but were fed from the incoming power to this box and not controlled by the switch.

Do you remember which wires were connected to the switch?
 

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Discussion Starter · #7 ·
There may be receptacles that are not working, but were fed from the incoming power to this box and not controlled by the switch.

Do you remember which wires were connected to the switch?
I found a light with a switch on the circuit no longer working. But I haven't used it for 15+ years.
It had power from the circuit, but not controlled from this switch.

So the switch can actually act as a pass through on power?
And that's what might be happening here?
Sorry for my ignorance... :)

Is there a good way, or tester, to help determine which wires are going where on the other end?
 

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I did.
And it did.
Then put it back the way you found it. Easy peasy, done and dusted.

Here's what you don't understand. There is no secret shibboleth to tell electricians what those wires do. There is no schematic on file at City Hall. The only storehouse of knowledge on what those wires are doing is how they were connected before.

Once that knowledge is destroyed, recovering it requires a higher level of skill. There's not a thing you can order on Amazon to fix it.


On the right switch, I'm hoping that black-white pair both go into the same cable. That would make it an old-style switch loop, which means it's totally separated from all the other wires and must never interact with any of the other wires. (except for safety ground; ALL safety ground wires go together).

Other than switch loops, there's no earthly reason for a white wire to go to a switch, unless it is a "pigtail" from a wire-nut full of black wires. Sometimes, white is used in 3/4 way switch circuits, but there'd be a RED wire around if so!

Of course, after the drywallers are through, all wires are white :)

The fact that the wire-nutted white-white pair and black-black pair have a pigtail on them, tells us they have 2 jobs:

  • The supply always-hot and neutral cable from the breaker.
  • Always-hot and neutral going onward to other switches and receptacles.

I really can't grasp why a switch would have 5 non-ground wires going to it, especially when 2 are neutral. You have told us nothing about the switch, and I suspect someone wired a 3-way circuit improperly.

In which case, no wonder you can't figure it out!

Fortunately we now have smart switches, which allow correcting such defective wiring without pulling new cables.
 

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You really need to pull the wires out and separate them better so we can see in there. Also were there 2 switches ? and what conductors were on the switch- I assume the long ones. Why are the white wires disconnected in the box?
 

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To trace wires in the wall you can get a two piece kit containing a battery operated tone generator that you clip onto a wire end in question and a battery operated tone receiver that you move over the wall surface like a stud finder or a wet paper towel or a piece of sandpaper and it sounds the tone through a small loudspeaker. Each of the two pieces might be vaguely the shape and size of a cigarette pack or a cigarette lighter or a miniature portable radio.
 
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