There is a piece of a circuit, but not an entire circuit, that is not working in my house. Its bizarre and I cant figure out what is wrong. A couple of lights and outlets aren’t functioning any more. I thought it might be a bad breaker but it’s only part of the circuit so it can’t be right?
I don’t want to pay someone to trouble shoot this as i can replace a breaker no problem but I’m not sure the breaker is bad. This all started happening just a couple days ago.
Any ideas to try? I’m baffled.
Check the outlets on that circuit. One may have a loose connection causing the circuit downstream to not work (or a GFCI that may have tripped). Turn off the breaker before opening them up. You may have to turn it on to test with a volt meter, making sure the exposed wires aren’t touching anything when you do. Call someone if you aren’t sure of doing this yourself.
loose wire in an outlet. find the last outlet that is always good. That pins down the problem. It is either in that outlet or in the next one.
This assumes, of course, that you can figure out in what order the outlets are wired.
Hmm sounds reasonable. The last one that is good will point me to the bad one? I need to figure out which outlets are on that circuit though.
Check to see if there is a GFI outlet on the circuit. It it has tripped the circuit will be down (but the breaker could be still ok).
I agree with almost everything. A loose connection is most likely the problem. This is becoming more common as home age. Some still have aluminum wiring that is more prone to losening. A simple VOM can help check for voltage, but it won’t do much for revealing a marginally loose connection. The poster or electrician needs to check every connection possible in the series. If he has GFCI’s , that’s a further issue possibly involving other ground wires, even at the load center.
Caution here: What you describe having to do with a likely loose connection is a source of arcing or sparking. A GFCI won’t detect arcs. Arcs are sparks and they can cause fires that the GFCI or circuit breaker will never detect. The latest NEC code is the standard in most locals and arc fault sensors must now be used in bedrooms and other areas to prevent fires. You have a potentially serious problem. Do not leave items plugged into those outlets until this is resolved. There should be no arcing with nothing pulling a load.
It probably is a loose connection somewhere, and based on what little I’ve seen you post in this thread, I would say this is not something that you want to fix yourself. You need to have someone who knows a lot about electricity to track down the problem and inspect the whole circuit. This is exactly the sort of thing that can burn your house down.
That’s my opinion, anyway.
(I’m an electrical engineer with a couple of decades of experience, by the way)
I’m an electrical engineer too hehe. I’m not an electrician though. I was looking for some tips to start troubleshooting.
It’s not rocket science to turn off the main and go outlet by outlet looking for a loose wire.
If it’s a light then I would pull the outlets nearest the switch first. Nearest could be a socket on the other side of the wall. If you have an attic then you might be able to trace the general layout of the wiring.
You may be an EE but if you do not know where to start I would suggest that you start by getting in a wrench turner. but if you must.
unplug everything from the dead outlets. Start with a VOM. check each outlet for voltage from hot to neutral, then check between hot and ground, then check neutral to ground. If you do not get any voltage between set, check for continunity between each. If you do not get any continunity between grounf and neutral and no voltage then then you have a complete wire broken. AS others have said either the first outlet not working or last working outlet in circuit.
Also are your sure that it is only part of a circuit? Have you mapped out the different circuits? You might want to test each breaker with a meter to be sure they are working.
No, it’s not rocket science, but let’s say you do find a loose wire. Is it because the yutz wiring it up originally didn’t tighten it enough? Is it because the circuit is overloaded and it is overheating and getting loose? Is it overheating because some moron swapped out the 15 amp breaker with a 20 amp to stop it from blowing all the time? Is it aluminum wiring and did some yahoo replace the outlets and didn’t use the proper type or use a splice? Is there some sort of corrosion problem that needs to be addressed?
If you know to look for all of these sorts of things, then sure, do it yourself. It’s not rocket science, but it is a bit more complicated than just tracing down the circuit and looking for the first loose wire you find.
By the way, if you are having trouble figuring out how the outlets are wired, you can get a circuit tracer for about $50 or $60. These have a small transmitter that you plug into the outlet (turn off the breaker first), then use a wand type thing to follow the circuit through the walls. As was previously posted, the most likely source of the problem is either at the last outlet that works, or the first outlet that doesn’t. It could be somewhere between there, though. You aren’t supposed to hide junction boxes inside of walls, but sometimes people do, and sometimes that’s where the bad connection is.
some points because people of all skill levels might read this and use as guidance.
checking for voltage is done with the circuit breaker on.
checking for continuity is done with the circuit breaker off.
you figure wiring path by visually following wires and the basement and distance from the breaker box. things in a circuit are often wired sequentially in a serpentine manner though you may find a branching sometimes.
you can find any nonworking (no voltage when breaker is on) receptacles and can guess the last working on in the sequence, though that is not absolutely important. if it is a bad connection it could happen at the wire leaving the last good one or in the wire coming into the first bad one or in the wiring in between. if you have to remove more than two cover plates to find this it is no big deal, so don’t sweat finding the last good one/first bad one.
it is good to have a map of your circuits so you could make a map for all your circuits for the future. for breakers that aren’t clearly marked you could test. for the fewest steps turn all the breakers off for lights and receptacles, turn one on and find all the live lights and receptacles. turn the other unknown circuits on one at a time testing all untested lights and receptacles. your map won’t be complete until you haven’t fixed your problem and had all working circuits.
a bad connection is a likely cause. with the breaker off for the problem circuit; remove the cover plate of a receptacle (if you can estimate the last good one or first bad one then start with these two) test for voltage both in the slots of the receptacle and on the wire connecting screws on the sides of the receptacle (you don’t know it is dead until you’ve done that) before proceeding. look for a visibly loose wire, you can wiggle the wire gently, if the wire is inserted in the back of the receptacle then you need to unscrew and pull out the receptacle to check (inserting wires in the back is a frequent cause of bad connections, a poor wiring method done to save time, i refasten under the screws when i see them). continue with this process until you have found the problem in the nonworking receptacles.
the problem can be solved by checking for voltage and deducing continuity. if continuity has to be checked then a battery/light continuity tester can be bought for a few dollars, it takes a few more steps to use compared to the expensive testers but that might be OK for a one or seldom used device.
Update:
It was an outlet in one of the bedrooms, at the top of the house. Kind of surprised that it wasn’t one in the basement as I figured those would come first in the chain before the upstairs outlets.
Anyway, thanks for all your help!
(As an aside, how much money did I save from calling an electrician so I can sell my wife on buying a toy 
)
According to an online estimating site I googled, you just saved yourself somewhere between $60 and $90. Tell your wife it was an even $100 and go spend that. 
By the way, what exactly was the problem with the outlet?
There was a big wire nut behind the outlet that came somewhat loose. Once I re tightened it everything was fine again.
I’m not disagreeing with you but look at what I said. It’s not rocket science to check for a loose wire. It’s like saying it’s not rocket science to put on a bandage. Doesn’t mean a person should attempt surgery.
A loose wire is a simple repair. Burnt wires mean there is more to the story. Looking at the outcome, it was a wire nut which was probably put on before back when it wasn’t code to tape them. It’s easy to put on a wire nut and then, through the process of stuffing it back in the box have a wire loosen up. I’ve recently gone to the push-in buss connectors to clean up multi-switch boxes. I wish they would introduce the European buss connectors I’ve seen that use screws to secure the wires but that’s for another thread.
Cubsfan, if you haven’t done so, you might want to tape the wire nut to keep it from backing out or coming in contact with a ground wire.
It’s code to tape them now? News to me. I rarely tape wire nuts. Generally only do on dedicated circuits to prevent someone from coming along later and using it for a new branch.
I’m still uncomfortable using push-in’s in boxes. Not a rational fear but I equate them to the push in connections on outlets(back stabbing) that have caused many issues over the years. Legal and for the most part safe, but not the best method.
I only use them for fixtures and at that mostly just fixtures that included them to begin with.
Every job should yield a new tool