Funny yet sad electrical story...

[Steve Wurster]

Here's one I never ran into before. I've got a light switch in the unfinished part of my basement that I want to tap a new fixture into. The original owner of my house setup this switch and it's pretty crazy. There are 2 lines going down into the switch, and one line coming out the bottom. The line that comes out the bottom makes a 180 and goes right back up parallel with the other 2 lines, and all 3 spread out all over the basement. I can't figure out what goes where, which is the actual power, etc.

Anyway, there's enough slack in that line on the bottom for me to cut it and splice in the line from my new fixture. Bit of a pain due to where I put the new box for the splice, but I manage to tie the lines together. I turn the breaker back on and all the lights come back on except my new one. Hmmm... I turn off the switch and all the lights go out but my new one turns on. What the heck?! How did that happen?

I call my Dad and he said black is probably swapped for white somewhere in there, and suggests I wire the black from my new fixture to the white lines from the line I cut, and vice versa. I do that and no change to the light behavior. Now I have no idea what to do. I probably should have tapped right into the switch, but I think that box may have hit its wiring limit. Of course I probably could have gotten a bigger box to avoid this problem, and I may end up having to do that. I've got another call out to my Dad; waiting to hear back.

So it's funny that I'm running into this, but damn if this isn't sad. Ugh.

[Ryan Mooney]

I found the same problem under our sink. They had swapped hot and neutral at one of the outlets when they "split" it so half was on a switch (for the garbage disposal) and half wasn't (for an under sink hot water heater long since removed that the PO had tapped onto the garbage disposal circuit). Worse they were switching the neutral on/off which is a bit of a problem safety wise. Finding the problem may be a bit of an adventure.

Two things can help:

Buy a toner so you can find all of the outlets on that circuit. This makes life SOO much easier (breaker OFF of course of bang goes the toner).

Continuity tester. At each outlet the ground and the neutral should have continuity to each other and the hot should have continuity to neither regardless of which position the switch is in. If you start drawing it all out you ought to be able to figure out where things are flipped.. eventually.

[Myk Rian]

Continuity tester.

^^^This^^^
They're handy to have around. The type that plug into the receptical.

[David G Baker]

Any possibility of it being a three way switch?

[Mark Bolton]

The three wires isn't anything uncommon. Likely a hot in, hot out, and a switch leg. If you just take it about and test/trace the leads you would likely figure it out.

Be careful though. No offense but it sounds like you could easily get zapped or start a weenie roast.

[Steve Wurster]

I do have a multimeter in the house. It's actually my Dad's; it's been here for a few months for another reason and he never took it back. I was just talking to him and I mentioned the tester; he said I should be able to use it to check hot vs. neutral. He's out of state right now and so can't come over to look at this with me. Like me he's a visual guy, and so explaining this to him over the phone doesn't help too much.

This switch is not a three-way switch, but one is involved. The feed for my switch actually comes through a three-way switch that controls the main lights in the basement. This means that if I'm in the shop and my wife or son goes upstairs from the basement and turns off the lights, the lights go off in the shop as well. What's worse is that this circuit also controls my office, so I have to turn off our computers, the cable modem, etc. in order to do this work. I'm not touching this stuff again today primarily for that reason.

My current thought is to get a bigger box for the switch and rewire the whole thing. That should allow me to have all lines come in from the top, and have enough room to hook everything together. Before taking it apart I should be able to use the tester to determine hot from neutral. Otherwise I'm pretty much back where I started.

And don't worry, Mark, I cut all the breakers for the basement when I'm working on this just to be sure. It is definitely true that one or both of those lines that come into the switch from the top still have power if I only kill the breaker for the office and shop lights. The lines are right next to each other and so my little tap-style tester can't tell one from the other. But if I kill the remaining basement breakers there's no more power in any of those lines. If there were I think I would have known by now. :-)

But I'm not an electrician and so my knowledge here is definitely limited. I know enough to wire things up and I always cut the relevant breakers, but otherwise I'm hitting the edge of my knowledge.

[Jim Koepke]

This switch is not a three-way switch, but one is involved. The feed for my switch actually comes through a three-way switch that controls the main lights in the basement. This means that if I'm in the shop and my wife or son goes upstairs from the basement and turns off the lights, the lights go off in the shop as well.

This sounds like someone started to have a set up for the basement stairs so they could be turned off and on at either end.

I grew up with this stuff, made my living in the electronics industry and still find it sit down and draw it out confusing. I can only imagine what folks who do not really know much about the workings of things electrical end up doing.

Well, I do not have to imagine some of it. I have had to tear out old wiring and replace it many times. But the way of the inexperienced are many and often have unreasoned approaches to solving a problem.

Hmmm... I turn off the switch and all the lights go out but my new one turns on. What the heck?! How did that happen?

If a switch turns one circuit on and simultaneously turns another off it either has to be a multi-way switch or one of the circuits is wired across the switch. One way to determine this is to unscrew all the lights that are off. If the one on when the switch is off is wired across the switch, as you unscrew the lamps that were off the one that is on will get dimmer and as you get to the end of unscrewing the ones that are off they will start to glow. This of course depends on the wattage of the lamps involved and that there isn't anything but lamps in the circuit.

For testing hot versus neutral, measure to ground. Make sure you have a good ground. Depending on your multi-meter even with the power off you may see some voltage on the wires. This could be anywhere from a few millivolts to as high as about 10VAC. This is just induction from the wires being next to live wires.

This can be confusing for people reading a very low voltage on the neutral which should be tied to ground by the power company and somewhere near the service entry point of the building.

jtk

[Brian Elfert]

Too many wires in a box is not going to cause the issues you describe. You could have 20 wires in a box and everything would work fine if the wires are hooked up right. I believe part of the worry with too many wires in a box is that the pushing required to get all the wires into the box could loosen up a wire nut causing heat and a potential electrical fire.

[Doug Arndt]

There are 2 lines going down into the switch, and one line coming out the bottom.

Are you saying that the switch has two screws on one end, and one screw on the other ? If so, that's a 3-way, and the pair of wires are travelers, they go to the other matching switch. Do not connect ANYTHING to either of those wires. Doing so will give the symptoms you mention.
It's also possible the the lights are actually connected to one of the travelers (meaning the current installation is wrong)
What color wires do you have ? also watch for a white/any wire that might have a turn of tape around it -- "marking" it hot.

You said there is a 3-way in here, open up both ends (find & open both 3-way switches) and confirm that the 2 wires that attach to the switch on one end, only go to the other switch the same way, with nothing else attached to them at either end. If this isn't the case, you've got a bigger problem and will need to first figure out how it's wired and how it should be.
Good luck, but it sure sounds to me like a 3-way wiring issue.

Besides the 3 wires you mentioned, any other wires in that box ?
If so, describe the colors and what goes where.

[Steve Wurster]

The stairs going down into the basement are lit by a 3-way switch; one switch at the top and one at the bottom. The switch I'm dealing with is downstream from these on the same physical line, but is not directly tied into these switches. That is, if the lights are off in the basement then they are also off in my shop. The switch in my shop does not affect the lights elsewhere in the basement. I think the idea here was that you would not expect someone to be in that area of the basement unless the lights were on in the basement. The fact that they're all tied into the circuit from the office is the really annoying part.

I have not looked at the wiring of the 3-way switch, nor of the switch I care about. Somewhere in this whole system there's a mixup; I just haven't figured out where yet. I was out of the house all afternoon until now and so I'm not planning on revisiting much of this until Sunday morning at the earliest. It's more complicated by the fact that at least one of the 2 lines heading down into my switch go through another box in the basement that contains nothing but a few splices. I have no idea where those other lines come from; everything is behind drywall that I don't feel like messing with. If I ever find the original owner I might have to have a word with him.

At my switch there are 2 physical 14/2 wire cables coming down in from above and one physical cable going out the bottom. That third line on the bottom only goes out the bottom because the 2 openings on the top were already taken. I'm not exactly sure how the switch is wired; I'll look at it later tonight or tomorrow. There is a limit of wires allowed per box based on the physical volume of the box and the wire gauge used. It's usually written on the inside back of the box. Not that people don't shove more wires into a box than they should, but I do like to follow those guidelines.

I think tonight I'm going to see how my switch is wired (without physically touching it) and write it down. That way if I do decide to rewire it with a bigger box I at least know how it was to begin with. Maybe I can see the problem just by looking at it in more detail.

Thanks for the help everyone. I'll let you know tomorrow how my progress is going.

[Ed Aumiller]

You are connecting to a 3-way switch... you NEVER have just one three-way switch... there has to be TWO of them.... get a book on wiring up three way switches and you will see very quickly what is going on...

[Jeff Erbele]

I do have a multimeter in the house. It's actually my Dad's; it's been here for a few months for another reason and he never took it back.
....
....
But I'm not an electrician and so my knowledge here is definitely limited. I know enough to wire things up and I always cut the relevant breakers, but otherwise I'm hitting the edge of my knowledge.

Respectfully:
1. If you borrowed the multi-tester, your Dad shouldn't have to come get it.
2. Right. Hire one.
You are having difficulty explaining what you have, because you don't know what you have.
As much as I understand, it sounds like there may be at least one pre-existing wiring problem. Adding to it will not end up with desirable results.

[Steve Wurster]

Ed: There are a pair of three-way switches that control lights in the basement. Half the lights they control are on the finished side, the other half are on my shop side. Those on the shop side have a separate switch sitting in front of them. So they can be turned off even when rest of the lights are on in the basement. I tried to tie into one of the lines that is connected to that separate switch, but apparently hot and neutral are switched in there somewhere. The problem is where.

Jeff: I didn't borrow the tester. My Dad brought it over to look at the 1970s era pinball machine we moved from his house to mine. It doesn't fully work and so we were going to take a look at it using the tester, but we never did. That was a couple months ago; the tester is still sitting on top of the pinball machine. Both him and I forget that it's there. Heh.

But you are right that I don't know what I have here. The original owner did this work, and it's partially scary. I'm more afraid of that separate box that just has splices in it, because I have no idea where they go. Not that I can easily trace the lines on the switch I care about, as they just join other lines up on the ceiling. This thing is ugly.

My plan for today is to rewire the switch I care about into a bigger box. If I can't figure out from there how things are wired (hot vs. neutral) then I'm going to call an electrician. I would really like to separate the office circuit from the basement circuit, and doing that definitely requires an electrician. Not that even doing that would be possible depending on how the original owner tapped into that circuit.

[Steve Wurster]

I removed the wires from the box and put everything back into a larger box. I left my new light completely disconnected. This is what I found by capping all the lines and then testing each with various circuits enabled...

The line from breaker 27 comes into the box and is connected to, at a minimum, some outlets in the basement. The old fridge I have right next to this switch area is plugged into this circuit. The box here is just where the original owner completed this splice between the feed from 27 and the line that goes to the outlets. I'm guessing that perhaps at one point he thought about connecting circuit 27 to a switch. Either that or he just figured this was a good place to make this splice. I have no idea what other outlets are connected to this circuit; I didn't bother walking around the basement checking outlets or other lights. The strange part with this splice is that the outgoing line is 14/3 wire, but the red line is simply capped. The incoming line from 27 is definitely just 14/2 wire. This 14/3 line does NOT go to the 3-way switch for the stair lights (more on that below). I'm guessing the original owner just used 14/3 wire here because that's what he had. Seems like something he would do...

The line from breaker 13 comes into the box and is connected to the switch. The switch ONLY has one black and one white wire connected to it. Circuit 13 is the one that also feeds the 3-way switch for the stair lights, as well as feeds the office on the first floor. Since the switch only has one black and one white, that means the power for the lights is coming in from the 3-way switch, through the lights, and then down to this separate switch. At least I think my theory on that one is correct. I'm only used to switches where the power comes in from one end and the switched light or outlet is on the other. But that's not how this is wired. I *think* I can just tap my new light directly into this switch, but I think it's time to consult an electrician.

In case you were wondering, all the ground lines in the box are tied together and grounded to the switch.

For memory purposes, I marked the lines connected to circuits 27 and 13 in three places: The physical cables themselves, the wall behind them, and on top of the new fixture box. Should make it easier to remember what is what.

[Jeff Erbele]

Ed: There are a pair of three-way switches that control lights in the basement. Half the lights they control are on the finished side, the other half are on my shop side. Those on the shop side have a separate switch sitting in front of them. So they can be turned off even when rest of the lights are on in the basement. I tried to tie into one of the lines that is connected to that separate switch, but apparently hot and neutral are switched in there somewhere. The problem is where.

Jeff: I didn't borrow the tester. My Dad brought it over to look at the 1970s era pinball machine we moved from his house to mine. It doesn't fully work and so we were going to take a look at it using the tester, but we never did. That was a couple months ago; the tester is still sitting on top of the pinball machine. Both him and I forget that it's there. Heh.

But you are right that I don't know what I have here. The original owner did this work, and it's partially scary. I'm more afraid of that separate box that just has splices in it, because I have no idea where they go. Not that I can easily trace the lines on the switch I care about, as they just join other lines up on the ceiling. This thing is ugly.

My plan for today is to rewire the switch I care about into a bigger box. If I can't figure out from there how things are wired (hot vs. neutral) then I'm going to call an electrician. I would really like to separate the office circuit from the basement circuit, and doing that definitely requires an electrician. Not that even doing that would be possible depending on how the original owner tapped into that circuit.

Steve,
I hope I wasn't to harsh about returning tools and it appears you took it all in stride. Loaning tools is a real sore spot with me, with several very negative experiences over the years, tools never returned, or damaged, costing me lots of money, time, and the inconvenience of not being able to use what I owned when I need it.

The more you wrote in this post and the next, the more I think an electrician would be in your best interests.
I wish I was your neighbor; I would like to see your science project and tackle it. Until you can trace all of the circuits involved and draw a functional schematic I doubt you will solve it; or I from afar based on the written descriptions. Based on your descriptions I am certain parts of your house are improperly wired; probably by the last home owner. Partially finished (sheet rocked) makes it a little more difficult in that you cannot visually trace wires, but not impossible with electrician tools basic to the trade. Testing tools tell you all you really need to know.

Hire an electrician. He/she will figure it out rather quickly, make it right, safe and legal (code compliant). It will be money well spent.