How to Find a Dead Electrical Outlet Without Removing Drywall

"...the likelihood a wire broke somewhere in the wall is going to be very low..."

I just finished a job where a broken wire in the wall WAS the problem- actually, the wire was pretty cheap, and the insulation was damaged when it was originally pulled into the conduit. With time and excessive humidity, we ultimately had a short to ground which resulted in an open on the live wire. Very difficult to find, because the ground fault was actually intermittent...Pulling new wire fixed the problem.

All factors being unknown, the likelihood a fastener could have damaged a wire is not out of the question.

sometimes rodents chew on wires that they can get to (and they like to nest in loose-fill insulated or non-insulated) walls/ceilings).

Sniff for decaying rodent?

Hmm. 30 years in this house, and never smelled one. Thanks for the nightmares (joking) but I don't think that's it.

Thanks

Pull the last "good" box and remove the wires. As AH says, there should be 4 wires. Two will be hot, two will be dead. Ring out the dead wires to the last box. If that circuit is good reassemble everything and it should work. If you get no signal from bare wire to last receptacle, you may have to pull new wire between the two. Or abandon the receptacle. The terminations are very likely the problem.

How about "back powering" the dead socket? Then you can use your "live circuit" detection method. Just make up a male-to-male short pigtail harness, then you can use a regular extension cord to apply power to the pigtail. You could just put a second male "plug" on the extension cord itself, but why ruin a good cord when all you really need is short section to get from extension cord to wall socket. Just be sure to make all the pigtail connections first, then plug the extension cord into a live socket, not the other way around, or you will have 110V (or your local residential AC supply voltage) on the male ends of the pigtail connection!

Tom

Destroy the male to male cable after you have done the job.... don't want anyone plugging it in.
Del

NEVER !!!

NEVER !!!

NEVER make a male - male power extension cord !!!!!!

44M,

I understand your concern about this type of cord, but I think we covered the safety issues sufficiently. I covered the plug-in sequence, and Del (our resident cat) added to "disassemble the cord" once the task is done (something I probably should have added myself). Any tool can be dangerous if used in correctly (if I poke myself in the eye with a screwdriver, I'm probably going to be short one eye ). This is also the reason I described making a "short pigtail", instead of converting a longer extension cord. With a short pig-tail adapter, the most you could do is plug both ends into the two outlets residing in the same outlet box, which would usually be a non-event. We are assuming (I know, a dangerous thing!) that the OP has at least a rudimentary understanding of electricity and wiring. His description of the problem tells me he's not clueless when it comes to residential wiring. Thanks for the reminder; no matter what, SAFETY FIRST!

Tom

Using the same phase, any other will cause a possible short.....

Good point, Andy! Thank you for the reminder. I probably won't need to use this method, since so many others have been offered, but if I ever do, I'll surely keep that in mind!

Micah

Thank you all for your help, and please, keep the ideas coming. I have too many of these kinds of problems, and your brains obviously work better than mine. And, yep, Del, I will. I have 6 grandkids, and I'll just bet they could figure out a creative way to make sparks with that.

Micah

If you do everything mentioned above, and find the problem is in the wall (where a mouse committed suicide) you can try to find the break using a non contact AC voltage probe. they are cheap... I used to have one, still do somewhere, it worked really well, would light up when I came within a foot or so from any live wire.

http://www.testersandtools.com/Voltage-Probe-Non-contact.php

Well micahd02,

I had to solve this problem under very expensive velvet wallpaper - no room for error. I was looking for a light switch buried by the dry-wall guys. I ran into a phone company gentleman who shared his square 6volt battery and buzzer with me.

He jumpered from one of the battery terminals to one of the dead circuit wires at the light, and switched the buzzer on. Then he got out his old AM radio, a cheap one is best, setting it between channels for maximum 'white noise' and medium volume. Holding this little radio against the walls he walked along until the 'buzz' from the dead circuit wire came through the radio, slid it vertically and horizontally to pinpoint the best guess.

We made our first test hole right into the center of the buried switch box.

There are commercial versions of this perhaps, but perhaps my experience could lead you to an inexpensive and immediate solution. CJM

Very cool story CJMcGill.

Still by "buzzer" do you mean a powerfed?

Just trying to get this clear in my head.

Did the Buzz come because the fed wire became the end of the antenna?

I would have thought the feed back towards the circuit break would have buzzed, and then stopped buzzing at the break.

In an earlier similar sort of discussion question seems a Megger Meter was used to tell how far it was from the end of a dead circuit, to the point of break.

Last Saturday when the Phone Technician came to repair our phone and DSL service, I asked him if a Megger Meter would tell him where the line was dead from simply clipping to the dead end. He said he didn't know what a Megger Meter was, but that the meter he had, would do that, so he guessed it had that function.

By "switch box" do you mean really "junction box", for those are common to bury in a wall.

In cases where for one reason or another an underground leg is broken, with no obvious event like a run in with a Ditch Witch, what tools are used to determine the fault?

The buzzer was a small cube with 2 terminals, probably from an old doorbell. The opening and closing of the DC to make the buzzer work was all it took to turn the dead wire into an antenna.

CJMcgill:

I missed something in your description. If it was a buzzer opening and closing, that required a complete circuit. That in turn would have to be made between the terminals of the "dead" outlet (the Device Under Test) and the next outlet down the line, with a battery/buzzer circuit at one end, and a jumper across the socket at the other. But if I knew where to put the jumper at the distant end of the section, I wouldn't be hunting for this problem, since that other end would be the power feed to my end. I missed this earlier. Or am I missing it now?

Micah

I too was also thinking like an electrical person when this method was shown to me by a communication tech., so I was surprised that it worked so well. The only complete circuit is from one terminal of the battery, through the little buzzer, and back to the battery.

The jumper from one of the buzzer terminals over to the dead wire gets the wire to transmit like an antenna, not like a circuit. It probably gets capacitively charged then uncharged repeatedly due to the rapid switching on and off of the buzzer.

I would try the neutral wire just in case there is a partial circuit or a bad connection that could possibly energize while you are working with it. CJM

Good point. Thank you, a lot. I will have to dig out one of my old battery buzzers and give that a shot. And its interesting how the old tricks that rely on mechanical devices sometimes are the only ones that still work. Try this trick with a piezo sounder and I'll bet, since the signal created is only in the audio range, it wouldn't work at all. But the RF created by the buzzer make-and-break operation is probably the cause of it working with a mechanical buzzer!

A portable "CB" radio will do the same without the jumper wire...

bwire,

Does the CB radio send the signal or recieve the signal? Can you give more detail? Thanks, CJM

Receive, if you manipulate the squelch; location of the break in the wire can be found very quickly, not unlike tracing a homing beacon.

Ten bucks... designed to locate breaks in power cables from 100Vac to 600Vac. available at any local hardware store (or big box store, if your so inclined)

It lights up, and vibrates when it is close to a power cable through the wall...

very easy.

My thanks to all of you who wrote before, and all of you who have chimed in since my last reply. I have been reading with interest, and (theoretically) applying your advice. This weekend I'll probably have a good chance to apply it in real life.

And, nope, I'm NOT unfamiliar with the risks inherent in residential wiring. I have done a fair bit of it myself, and followed my National and Local codes in the process. My problem here stems from a lack of understanding of how to FIND the problem once the wall was "skinned". So the safety advice is ALL well taken, and for that, I am most extremely grateful. It never hurts to read a reminder. As far as the necessity to sometimes exceed safety limits (the NEVER practices, I call them), I have been a test engineer in several disciplines, and learned early that testing, troubleshooting, etc., often requires rethinking a particular "NEVER", in order to get the job done. But I promise to exercise the utmost caution in anything I do with the advice I've received here.

That said, I'll try to let you know what else I've learned from doing after the weekend, and let you know how I've decided to handle it. I do, as a last option, have access to "home run" a new circuit. It won't be expensive, but I would rather fix it, and learn from it, than just replace it.

In the meantime, anyone else who would like to add their advice, please feel free. I learn every time I read here, so anything you wish to teach, I wish to learn.

Micah

Another idea:

Rent a device called a TDR (Time Domain Reflectometer) from someone who rents tools to electricians. You would need to discover which circuit this is on in your panelbaord and isolate it (lock off the circuit breaker). Then you can connect the TDR at the dead outlet and it will tell you how far away the break is. Once you know that, you can use a metal detector to find the wire routing in the wall by following from where you see it exit the box while measuring for the total distance the TDR shows you and voila! There's your break.

I used to routinely use TDRs in the Navy, to track down breaks in Antenna leads. Then Optical TDRs as a contractor at the Pentagon, to track down breaks in Optical Fiber. But I never thought to use one for plain old residential electrical wiring. I might check into this just to see what it would cost.

But when the wiring and copper plumbing (yep, 42 year old house, has copper plumbing) runs between the same pair of studs, I suspect I could easily wind up on a rabbit run. I'll have to check this out just to see if I can make it work. Good tool for the future, even if I don't need it now.

Thanks.

I did not notice, but somewhere in this string have you mentioned that at one time it worked, and now it doesn't; or has it always been this way?

I don't remember it ever working, but my wife says it did, once, then gave a spark when she plugged something in, and hasn't ever worked since. The rest of the circuit works, unless that one box was a home run to the panel (unlikely), because no other box in the house is dead. I pulled the duplex outlet from the box, and it showed no signs of damage, but I replaced it anyway. I metered the wires to the box, first (there are only two, plus the ground) and found no voltage, so I figured to first make sure I had a good outlet (they aren't expensive, so that was not a waste, at all), and then try to troubleshoot the circuit when I didn't have to worry about the problem being in the outlet itself.

Pulled the wires off the outlet, replaced it, replaced the wires, checked the breaker panel for a dead breaker (just in case), found none that were off or broken, and stalled out, unable to figure where to go from there.

I thought about using the existing wires to pull a new home run in (about 30 running feet of cable) but the pair to the box go UP, and the breaker panel is on the basement wall, one floor down. So wherever the circuit is fed from, it is above, and all the walls and floors above are finished, until you go all the way to the attic, which is two MORE floors up. Tall house.

So if I pull a new home run, I'm just going to have to bore up through the sill plate under the box from the basement, run the new wires, and abandon the old ones in the wall. I'm not looking forward to that, but it looks like its probably my answer, now, if some of the other troubleshooting ideas don't find it.

Have you considered the possibility that this outlet is controlled by a switch somewhere in the room? Maybe there was a lamp hooked up to it at some point.

Yep. Tried that out. I know all the switches in the room, and what they control. And the only one that WAS setup to control an outlet, I rerouted to a ceiling fan installation about 20 years ago. So, not that one. But it does bring up an interesting idea, I'll have to check out. If I find it, I'll let you know, and credit "Guest" with the idea.

Maybe give credit to (that) guest already. You didn't say whether or not (you ever observed) that outlet to work. Assuming a "house" situation like my own, when previous remodelling was done...the then improver found it impractical to impossible, to costly, or both, to restore current to the (soon-to-be) abandoned-in-situ outlet (and/or switch) while re-dedicating the loop to power facilities placed elsewhere.

As it (might have) turned out, that worker must have also found it more practical to leave a dead outlet, that to go to the trouble of removing cover and/or box and repairing (patching, tape embedding, surfacing, painting) the hole--choices left for you now to contend with.

Maybe ... give credit to (that) guest already. You didn't say whether or not (you ever observed) that outlet to work. Assuming a "house" situation like my own, when previous remodelling was done...the then improve-er, in the course of re-dedicating the loop to power access facilities placed elsewhere, found it impractical to impossible, too costly, or both, to restore current to the (then-soon-to-be) abandoned, in-situ outlet (and/or switch).

As it most likely turned out, that worker must have also found it more convenient/economical to leave a dead outlet than to go to the trouble of removing cover (and box?) and repairing (plugging, tape embedding, surfacing, painting) the hole—choices with which you are now left to contend...or not.

Maybe give credit to (that) guest already. You didn't say whether or not (you ever observed) that outlet to work. Assuming a "house" situation like my own, when previous remodelling was done...the then improver found it impractical to impossible, to costly, or both, to restore current to the (soon-to-be) abandoned-in-situ outlet (and/or switch) while re-dedicating the loop to power facilities placed elsewhere.

As it (might have) turned out, that worker must have also found it more practical to leave a dead outlet, that to go to the trouble of removing cover and/or box and repairing (patching, tape embedding, surfacing, painting) the hole--choices left for you now to contend with.

Now you have added an important detail, and I have a couple questions.

How certain are you that the box is a ground bonded item? You mentioned metering to the box. How feasible is it to run wires from a proven source to insure the test results? An extension cord would do the trick. You could test from the cord hot to the box and box ground wire, and validate the box ground bond, and also test from the box wires to the cord ground to verify all is dead.

From your wife's statement, it is even more important that you find the source end of that circuit. CJM