how to trace wiring for mystery switches?

Hi, we have two wall switches in our house, the functions of which are a mystery. Everything that seems to need a switch has it and works, but these two don't seem to be connected to anything. One is a one-gang in our living room. The other is part of a three-gang in our foyer.

I've accounted for exterior lights and floods.

I've tested nearby outlets to see if their split.

Is there an inexpensive way I can trace the wiring from the switch to see where it goes?

It's all under drywall of course.

--zeb

Reply to
Zeb Kagloonpop
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Depends on what you mean by 'inexpensive'.

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Reply to
Travis Jordan

If this is fairly modern construction either might go to an outside receptacle which might be split or totally switched (think XMAS lights). The switched outlet does not have to be nearby. I was in a home a few years ago where the lady of the house insisted on having one switch to control all the front of the house below the windows outlets for XMAS candles. They were split. Actually I think she had to settle for 2 switches because of the sheer number.

As for testing, start by making sure that both switches have wire connected to the terminals and then verify power using a test light from ground or white to one of the terminals. If there is power in and out of the switch then it goes somewhere (or did). I mention this because I have a switch in a 3 gang box that has no wires attached. It is just a place holder. I guess the sub was short a duplex box that day and used a triple.

Colbyt

Reply to
Colbyt

Of course!

First off, just a little personal opinion: If they ain't broke, don't let them bug you. OK, now a couple of educated guesses (I'm assuming this is a newer home, because people just didn't wire for "future use" up until the last couple of decades, if that long.)

Living room is for a ceiling fixture that doesn't exist? Or for phantom wall fixtures next to a fireplace? The point being that if it doesn't work anything you have now, it's terminated in a hidden box where the builder guessed you might want a light fixture(s) down the road.

The one in the foyer, following the same logic, would go to a covered weathertight box outside somewhere high, where you would possibly want a security light fixture. One other slight possibility there, maybe you have some outdoor plugs down closer to ground level that you don't even know are there? If so, they could very well be switch controlled. Bottom line: being in the foyer, I'm -definitely- sensing "outside" here.

Good luck, please let us know if you get a solution.

Reply to
I-zheet M'drurz

Or an "extra" was deleted from the contract.

Reply to
HA HA Budys Here

Maybe ice-melting cable outlets in the soffits, or a 3-way for some other obvious exterior light.

Reply to
HA HA Budys Here

if its a 3 way, looking at the switch will tell you. if it says on/off on it, its not a 3 way.

randy

Reply to
xrongor

Like a ceiling fan "light" attachment

Reply to
Rudy

I had phantom switches in two rooms. Being creatures of habit, we found ourselves flipping those switches DOZENS of times when we first moved in.

We had originally assumed that each of the switches controlled an outlet, for a lamp. We tried them all, with no luck. One day I looked up at the ceiling in the MBR when the light was hitting it just right. I saw what looked like a patched area maybe 5 inches in diameter. The previous owners of our house apparently didn't like ceiling fixtures.

About 30 seconds with a masonry hammer exposed an octagonal box. The wiring was still functional, controlled by the phantom switch. I installed a cheap "temporary" fixture that I had bought just in case the experiment was successful. That was about four years ago. ("temporary" is a bit of a joke in my house).

There is a similar "patch" in the foyer. I'll get to that soon. Maybe I'll put in something "temporary"...

Greg Guarino

Reply to
Greg G

"I have a light switch in my apartment that doesn't do anything. Every so often I switch it up and down a bunch of times. After a few months I got a letter from a lady in Germany telling me to quit it..."

- Stephen Wright

Reply to
Rileyesi
040811 1944 - xrongor posted:

Yes, and if both are 3-way, they may be working in conjunction with each other on a switched outlet in the living room. If they are both single pole, then they may be just working separate outlets. If the living room has two entrances, like one from the foyer, and another to a dining room or kitchen, then the probability of there being a 3-way system for lighting is greater.

Reply to
indago

Or in my case (old work), cut the hole too big and had to put in a 3 switch vice 2 box with the third switch not connected. Pull the covers and see if you have a phantom switch.

Harry K

Reply to
Harry K

Settlement tomorrow - Did walkthrough yesterday. New construction. One goal of mine was to identify each switch and what it did. There was one "future use" switch installed for a lamp post in front. It energizes a junction box in the basement set aside for the lamp post (Or what ever other thing I may decide to use it for) The electrician even labeled this box for me. Thanks.

Reply to
Brikp

If it's a simple switch, is there power coming INTO it? (is one of the wires "hot"). To test, I'll stick a 3prong orange extension cord in and bring it along to the outlet. Now I have a know good ground next to me.

Meter goes into ground and then I touch other end to either side of the switch. Is one of them hot? Good, you know which one to not grab ;).

Toss a bit of electrical tape around it just for kicks and marking.

Okay, at this point, were it me, I'd draw how it's wired to the switch, pull the switch out and disconnect the wires.

That hot one? We know where it goes, that's fine.

The other two (you hope two), should go to the end of the line.

I'd use my toner and inductive amplifier (too much new, cheap on ebay - around $40 for the pair). It's used to trace wires in the ground and walls. I own one because I run network cables all the time. This lets me know which one of 20 in my hand is the one in office 15.

In THIS case, I'm going to SHUT OFF THE POWER TO THE HOUSE. I might not need to. But it doesn't hurt.

First, I'll check the two wires. Is there continuity? (this might mean the other ends are wired together).

Is it continuous with GROUND? (likely not, as the switch would cause a short quickly if there's hot to it).

Then I'm going to attach the toner to two of the wires that I hope go to the destiantion that the switch controls.

The "inductive amplifier" is basically a chunk of metal point that makes like an antennae and a speaker.

The toner makes a, er, TONE. Actually too. Sounds like a british police car. Doo DOO doo DOO doo DOO. I take the speaker part and start to go along the wall from the switch.

In my case, tracing a mystery coax cable from my basement, I found that the wire went along the floor of the kitchen, under the refrigerator and into the wall where the intercom is.

For you, it might be part of an old 3-way circuit (I've seen where people have converted it to "1 way" switch) or to a closed off light or (worst case) a switch to something with broken wires/shorts.

You can remove the switch, cap and tape off the hot wires (or all wires) and close over the switch if it's useless. I've got this on a switch for an outlet which has my stereo/vcr on it (we kept switching it off as we left the roof. Pure reaction to seeing switch by door.)

Reply to
chuck yerkes

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