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New Home Old Wiring--Adding Switch/Outlet Middle of Run

8298 Views 15 Replies 6 Participants Last post by  bethflorida
Good People

I moved to a new place (for me,) but the wiring is old. I'm adding a switch/outlet combo (Combo) to a 2 gang box with an existing 2 single pole switchs combined on the other side of the box. The old switches were wired in a way I haven't seen before, and I don't know how to add the new Combo. :(

The old switches have 4 brass screws and is installed with the writing "Leviton" is upside down. I'll have to speak in terms of top/down and right/left as I see them, even though the existing installation was "different" for me. The switches control an exhaust fan and ceiling light, respectively. Before I messed with the old switches, 2 outlets and the ceiling light in the adjacent room worked just fine! (Middle of run.)

As I said, the box is two gang. Four sets of 3 wires come into the box, all sets are white, black, and bare ground. The bottom right set of wires is the only one with power. All wires I don't mention were grouped together and capped. I jotted down a diagram of how it was wired, but now I'm not so sure I got it right. :confused1: There were 2 black wires connected to the lower right (as I saw the switches facing me) screw. There was one black wire attached to each of the top screws. I don't remember a white wire connected to the switches at all. The ground wires were attached at the back of the (metal) box, as there is no ground screw on the switches.

I know I need to use pigtails instead of putting two wires under a screw. Beyond that I need all the help you can give. Here are some of my questions:

1. The new hardware has 2 brass screws on my left, 2 black screws on the right and a green ground screw on the bottom left. I assume the black wires go to the black screws. Is that correct?
2. In replacing the existing switches with new ones, does it matter which black wire is on the top or bottom?
I first tried to put in the new switches hardware (not adding the Combo.) I assumed the bottom black (live) wire goes to the bottom black screw, the bottom white wire to the bottom brass screw, and the top wires and screws similarly attached. Only trouble is that when I wire the new hardware that way, neither the ceiling light nor the fan works. So what am I doing wrong?
3. And, finally, back to the reason I got started with all this, whenever I get the new switches in place, how do I get power to the Combo?

Thanks in advance for help in this.
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hope you turn off the circuit before you made any changes.
A photo would help. It sounds like you have it wired up incorrectly.
Reply to Redline

Redline

I hope your post was meant in jest, as it was not exactly helpful. :jester:

Yes, I tripped the breaker at the box (and checked the wires at the outlet in addition.) I agree 100% that things are wired incorrectly. That kind of caution is part of how I got to be this old!

And your constructive suggestion would be . . . ?

Beth
I am confused by the four black screws on your switches. Unless these are controlled from other locations as well there should only be two screws on each switch.
The new combo device should have two screws tied together on one side and one black and one silver on the other side and green ground.

Connect all the whites together with one pigtail. Connect the pigtail to the silver of the combo.
Connect the power in black to two pigtails. Connect one pigtail to the switch and the other to the double screw of your combo.
Connect the remainig two blacks, one to the other screw on the switch and the other to the single black screw on the combo.
Redline

I hope your post was meant in jest, as it was not exactly helpful. :jester:

Yes, I tripped the breaker at the box (and checked the wires at the outlet in addition.) I agree 100% that things are wired incorrectly. That kind of caution is part of how I got to be this old!

And your constructive suggestion would be . . . ?

Beth
Redline was just pointing out that pictures or your diagram would help us identify the details of your installation that you might have left out or misstated, in order to make sure we are all on the same page for the correct advice to be given.

Anyway, please consider the following:

1. You said it was a two gang box, but you only mentioned one device, a 2-switch device on the right of the box. Is there anything on the left side before you changed it, or was it blank?

2. Your existing device sounds like a duplex switch, which is one device having one switch on top of another switch. That explains the four brass screws.

3. Question: Do you know where each of the four cables go? One important question is whether the outlet and ceiling light in the adjacent room is fed from this box, or is just on the same circuit and is fed before this box.

How to tell:
A. TURN OFF POWER TO THIS BOX.
B. Disconnect all connections in this box, keep the wires separate and not touching anything.
C. With power back on, does the other outlet and ceiling light have power? If yes, it is fed from another circuit or is fed before this room.

If no, it is probably fed from this box. Then the four cables would be (1) power in, (2) power out to fan, (3) power out to ceiling light or lights, (4) power feed to outlet or adjacent room.

4. Did the ceiling light in the other room turn on (before you messed with it) when you turned on one of these switches?

5. Do you want the switch on the new combo device to control the receptacle that is on it, control something new, or take the place of turning on the fan or lights that one of the old switches used to do?


You see, the details need to come from you...there are several ways to have this wired, depending on the answers to the above questions. :)
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Thanks, will check

Willis and JoEd

Thanks for your questions/suggestions. I will take a careful look, try the suggestions and be back to you.

It really is great to have this kind of advice available. I know how to do the basics, but am learning as I go and sometimes a new situation is confusing.

Thanks again,
Beth
Here's what I see

1. & 2. The existing set up was a 2 gang box, with only the duplex switch on the right. The top switch, as it was set up (with the writing upside down) controled the fan and the lower switch controlled the ceiling fixture.

3. I performed the checks, and the power goes from this box to the adjacent room. Neither the ceiling fixture nor the outlets in the adjacent room worked when all the wires of the box I am working on were pulled out and separated.

4. Both the ceiling light and outlets in the adjacent room (bedroom) worked before I started messing with the box in the other room. Here's the interesting thing--when I connected the duplex switch white on both brass screws and black on the black screws, the outlets in the bedroom worked, but not the ceiling fixture. (Even though those connections did not make the duplex switch work.)

Joed--I'm working on my pigtails now. :wink:

Beth


Ok now I see why four wires on the switch. It is a duplex unit with two switches.
Tell uss all the cables coming into the box.
Recap wires

joed

Looking at the box, there are 4 sets of wires. Each has white, black, and bare ground. Only the wires in the lower right are hot. Juice must be flowing from this box for the next room to have power.

Beth
Beth - check out "Your Old Wiring" Shapiro. It's got lots of good information for a new homeowner of some old electrical work.
Shapiro?

Leah

Thanks. Is "Your Old Wiring" a thread here, a book, a web site, or something else?

Beth
joed

Looking at the box, there are 4 sets of wires. Each has white, black, and bare ground. Only the wires in the lower right are hot. Juice must be flowing from this box for the next room to have power.

Beth
Beth, you should tie all the white wires together, and extend a short piece from there to the silver screw on the recept/switch combo. Now you will need to identify what cable goes where. To do this, turn the power off, and connect your known hot black wire to each other black wire one at a time, turning power off each time before reconnecting.

In other words, turn off the power, connect the hot to one of the other blacks, then turn the power on, and note whether that wire goes to the next room or if it goes to a light you want switched.

When you have identified each cable, you will then tie the black from the hot cable to the black going to the other room. From there, extend a short piece of wire to the line side of the combo switch and another wire to the other switch. Then wire the remaining two wires to the two switches.

Of course connect all your grounds together and to your devices.
Understand now, but

InPhase and others

I did try this last suggestion, and think I understand it now. I know what goes to the ceiling light, to the other room, etc. Thanks so much.

I'll wire the combo switch just for the heck of it, but don't know if I can fit everything back in. Looking at the box, with so many wires and pigtails, there just doesn't seem to be enough room for the second device (combo switch.) With the other outlets in the house, they are all the same, 2 gang, but lots of wires and only 1 device. This dilemma seems more a matter of physics than electric wiring!

Beth

InPhase and others

I did try this last suggestion, and think I understand it now. I know what goes to the ceiling light, to the other room, etc. Thanks so much.

I'll wire the combo switch just for the heck of it, but don't know if I can fit everything back in. Looking at the box, with so many wires and pigtails, there just doesn't seem to be enough room for the second device (combo switch.) With the other outlets in the house, they are all the same, 2 gang, but lots of wires and only 1 device. This dilemma seems more a matter of physics than electric wiring!

Beth
Everything is a matter of physics, Beth. But don't panic! If neatly folding the wires back into the box doesn't leave room, you are probably capable of changing the box out to a bigger more modern 2 gang box.
Leah

Thanks. Is "Your Old Wiring" a thread here, a book, a web site, or something else?

Beth

It's a book. Author is Shapiro. I think I bought it on Amazon. As a newbie to old electrical, it is the best book out there for learning some basic techniques (like twisting wires) and what tools are useful. Also, it has some good info about 'getting to know your old electrical'.
physics

Everything is a matter of physics, Beth. But don't panic! If neatly folding the wires back into the box doesn't leave room, you are probably capable of changing the box out to a bigger more modern 2 gang box.

InPhase

Right you are about the physics, but in this case it's "wire theory" instead of "string theory." LOL

You are right, of course. A new box isn't that big a deal.

Thanks again.

Beth
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