3-way switch wiring

thefed

Thinks s/he gets paid by the post
Joined
Oct 29, 2005
Messages
2,203
Soooo....I've researched wiring diagrams and cant figure out whats going on

I have 2 switches in my bathroom, one at each end (there's 2 doors). In the past, you could turn either switch up or down and the light would go on or off....either one


Then, about 3 months ago, switch #1 had to be up....and # 2 could go either way....if you used # 2 to turn it on, then #1 would turn it off by going down....BUT only if #2 was in up position


Then, today, switch #1 is basically useless...regardless of its position, #2 does all the controlling...up is on, down is off


SO, I took a peak and switch #1 is a 3-way, while switch #2 appears to be a normal switch. My intuition tells me that the 3-way has 'gone bad' and simply needs replaced.

Can anyone lend some insight/experience? Thanks

Jason
 
Sure sounds like the 3-way is bad. Try replacing it with a new 3-way and see if it works as it did before all the drama with the switch positions.

I ran into an odd wiring job in my house....actually several of them when I was changing out switches and installing dimmers. Many of the 3-way lights had only standard switches. This made for a lot of frustration if someone turned out the lights from the distant switch as it would have to be turned on or off to get the other switch to work. I installed 3-way switches on all switches and it took care of the problem.
 
Soooo....I've researched wiring diagrams and cant figure out whats going on

I have 2 switches in my bathroom, one at each end (there's 2 doors). In the past, you could turn either switch up or down and the light would go on or off....either one

....

SO, I took a peak and switch #1 is a 3-way, while switch #2 appears to be a normal switch. My intuition tells me that the 3-way has 'gone bad' and simply needs replaced.

Can anyone lend some insight/experience? Thanks

Jason

Demons? Faulty memory? Someone played a trick on you and replaced a switch #2 when you were not looking?

There is no way that switch #2 is a regular 2-way and it worked in the manner you state. It takes a 3-way switch at each end to do that.

If it really could be turned on/off from either switch, they are both 3-ways - take another look. But it does sound like #1 just went bad.

One possibility - your description is not complete. For example:

SW#1 UP - A 2-way on SW#2 could turn the light on/off.

Now - IF and ONLY IF you leave SW#2 ON; SW#1 will turn the light on/off.

And - IF and ONLY IF you leave SW#1 UP; SW#2 will turn the light on/off.

But, if SW#2 is OFF; SW#1 will not turn the light on/off - only if SW#2 is ON.

So, you can turn it on/off from either, but only under certain settings. A 3-way on each allows you to turn it on/off regardless of the setting of the other switch.

Also, for that description, I assumed SW#1 UP = ON; it might be reversed from that.


-ERD50
 
Last edited:
My symptoms were similar if not identical in my kitchen. I had to replace one of the switches, it was cracked and IIRC became less operational as time went on. Until I replaced it I just taped it in the On position to make sure the other one worked. Make sure to replace with a 3-way as I'm sure you know. Under $5 and 20 minutes of your time and you should be done with it.
 
My symptoms were similar if not identical in my kitchen. I had to replace one of the switches, it was cracked and IIRC became less operational as time went on. Until I replaced it I just taped it in the On position to make sure the other one worked. Make sure to replace with a 3-way as I'm sure you know. Under $5 and 20 minutes of your time and you should be done with it.

I agree with RB, if switch # 2 is only single pole (regular switch) replace it with a three-way switch.

Is your wiring a bit old? Some of the old time electricians used two wire cable to connect three way switches. Modern practice is to use three wire cable and the only difference is that (with three wire) you carry a neutral wire along with the switch wires.

Good luck but I think you already have it figured out :)

Lance
 
I agree with RB, if switch # 2 is only single pole (regular switch) replace it with a three-way switch.

But you have to also have it wired to accept a 3-way switch.

If you don't have a background in electrical stuff, it can be a bit challenging to understand the whole 3-way switch set up. As some said, it can be done, and made functional, but possibly violate current codes (switching a neutral leg).

Even if you completely understand 3-way wiring, and know how to do it per code, it can be very challenging to actually figure out how the wires are run in your house in order to hook it up. I spent hours tracking down the wiring in my kitchen, and made pages of notes when I had some changes to make.

EASY SOLUTION: They sell remote control switches now. You replace one switch with the receiver; the other switch is actually removed from the circuit, and replaced with the remote control. The remote just tells the receiver to turn on/off, and of course, the receiver turns on/off locally with its switch.

You can add these to circuits that don't have 3-way wiring, or add them to any place you want additional control. I predict that within 10 years, it will be common for this to be built right into a little insert into a fixture (or even the 'bulb' itself) - they will be smart enough to 'learn' which switch to listen to, like the bluetooth learn modes today.

Remodeling : Outlets / Switches : Remote Light Switch : Home & Garden Television

Wireless 3-Way Decora Switch Kit (White) - 6696-W

<$40. An electrician will charge you more than that to ring your doorbell.

-ERD50
 
Agreed that there's something off about the original post, so it's hard to figure out exactly what went bad. But it does sound like most likely they are both 3 way switches and at least one needs to be replaced.

I'd stay away from x10 and other remote switches if you can... I tried them in my old place and they were always trouble, having to be reprogrammed under various power loss scenarios. And the few watts that they use constantly even when the light is off bothered me.

Three way switch wiring can be wild. I remember taking a look at my parents hundred-plus year old home, at an issue they were having with their three way switches. I ended up taking complete notes of what happenned in what switch position, and figuring out which wire was which was still a logic problem so difficult I was on the verge of writing a brute force computer program to try and solve it. In the end their old electrician solved their issue by some unknown means. It's a black art.
 
But you have to also have it wired to accept a 3-way switch.

If you don't have a background in electrical stuff, it can be a bit challenging to understand the whole 3-way switch set up. As some said, it can be done, and made functional, but possibly violate current codes (switching a neutral leg).-ERD50

Never, ever open the neutral! Never :rant:

The two-wire cable wiring method I described does not open the neutral. Its done by "ganging" (combining) switches so that there is a "hot" wire used at the source gang, then two "switch wires" running between the switches and finally a "neutral" used at the finish, the switch that has a wire going to the light. Even if the "source" switch was a single pole (regular) switch, a three way can (and should) replace it.

Its relatively easy to draw out on a piece of paper. Just get a do it youself wiring book and have at it :D

Anyway, if I were the OP, I would simply replace "like with like", changing out one switch at a time until the problem was resolved.

Chok dee! (good luck)
 
Never, ever open the neutral! Never :rant:

Agreed. 100%.

Maybe the way I worded the post made it sound like I was condoning switching the neutral? I'm not, absolutely not. I've heard of it being done, and it can 'work' - but it does make things less safe, and should NOT be done!

-ERD50
 
Agreed. 100%.

Maybe the way I worded the post made it sound like I was condoning switching the neutral? I'm not, absolutely not. I've heard of it being done, and it can 'work' - but it does make things less safe, and should NOT be done!-ERD50

No, not at all. But just in case anyone reading (this thread) some how though it was OK, I just wanted to make it perfectly clear that switching the neutral was never to be done :D
 
Oh man! This thread brings back bad memories of the electrical wiring in the basement of a house I once owned. The upstairs stuff was O.K. but the basement must have been finished later, with no inspection, by the electrical contractors Dumb and Dumber! I got everything straightened out, but it's a miracle nobody was electrocuted and/or the place didn't burn to the ground!:mad:
 
okay....ireplaced the first switch...nogo.then the second...still no go.


basically,the results are as follows: if either switch is in the UP position, switching the opposite switch does nothing. Conversely, if the 'other side' is down, you can switch up and down from where you're at.


this doesnt even seem possible as NOTHING has been tampered with....until the problem started of course...and even then, i just replaced the switched with identical 3-way switched


ideas:confused:?
 
I have this book in my bookshelf and find it extremely useful.

0aa8b340dca0f5760b6f9010._AA240_.L.jpg


Amazon.com: Step by Step Guide Book on Home Wiring: Ray McReynolds: Books
 
This should solve your problems and bring you inner peace:
 

Attachments

  • threeway.jpg
    threeway.jpg
    747.4 KB · Views: 12
wirediag.gif


Howstuffworks

thefed, T-Al's links are great, but looking at the physical layout might make it hard to understand how they are supposed to work.

Look at the pic above for a simplified version - it's doing the same thing, but just with direct connections rather than the back-and-forth physical wiring needed in real life.

So, both switched UP and you get current from HOT ->SW1 ->RED -> SW2 ->LAMP -> WHITE (Neutral or common, same thing). Lamp is ON.

Both switched DOWN and you get current from HOT ->SW1 ->BLACK -> SW2 ->LAMP -> WHITE (Neutral or common, same thing). Lamp is ON.

With one UP and one DOWN (either way) - there is no path for the current, so the light is OFF.

So, if the RED wire was missing, or broken, or disconnected somewhere, it would act exactly as you describe. But you said earlier that one of them was a 2-way switch, so I would bet that you don't have all the wires you need. Now, go back to T-Al's pic to figure that out (colors may be diff in your case).

-ERD50
 
Electronics was my hobby at one point, and I took a graduate level circuits course once, but when I open those electrical junction boxes, I apparently get stupid and confused easily. It usually takes me two tries to get it right.

And am I the only one who has a lot of trouble getting everything stuffed back into the box again? There never seems to be enough room for the stiff wires and the switches, especially if it's a dimmer or X10 type switch.
 
Only 3 things you need to know to be an electrician:
1 wire - hook up
2 wire - screw up
3 wire - give up

Being a plumber is easier. There are only 2 things you need to know:
1 -$hit doesn't flow up-hill
2 - payday is Friday
 
Electronics was my hobby at one point, and I took a graduate level circuits course once, but when I open those electrical junction boxes, I apparently get stupid and confused easily. It usually takes me two tries to get it right.

And am I the only one who has a lot of trouble getting everything stuffed back into the box again? There never seems to be enough room for the stiff wires and the switches, especially if it's a dimmer or X10 type switch.

Yep, makes me think it would be semi-interesting (as in I'll never really do it) to 'shadow' a real electrician for a day or two, just to see some of the 'tricks of the trade' (literally!).

I always need to sit down and draw out schematically what's going on. Then I scratch my head trying to figure out why they physically have all these wires going this way and that. But in the end, it always makes sense .... oh, they tapped from that circuit, and had to run it over there to feed that outlet, and the shortest way was through that box over there...

-ERD50
 
I suggest labelling wires. I use a p-touch labelprinter type device and then I just wrap the self adhesive labels around the wires. I can't tell you how much hassle this saved when I was removing some x10 switches I had installed in a three way circuit, repurposing one of the 3-way wires to get an always-on power feed.
 
I'll lay money on one or both of the switches somehow being miss wired with respect to the COMMON terminal. Screw terminal position on the switch means nothing, screw color or actual markings are the only way to identify the common terminal.

My FIL replaced a three way switch years ago and it took me about an hour to get it working right. What really makes it confusing is where the power enters the circuit. At the light? At the switch?

Time to start ringing out wires.
 
Soon after we moved in, the outlets in one of the bathrooms weren't working. I was about to give up and call an electrician, when I realized that they were tied to the GFI plugs in the other bathroom! So when the GFI was triggered in bathroom 1, which happens frequently, the plugs went out in bathroom 2.

Guess electricians make mistakes too.
 
Al...very common for a house to be wired with both bathrooms, a bathroom and a kitchen, or bathroom/kitchen and outdoor plugs all back to one gfci.

I'm sure theres a reason for this, other than saving a buck fifty an outlet.

My house has two of the three bathrooms, the garage outlets, and the outlet on the back of the house all wired to a single gfci in the laundry room. My old mcmansion had all the plugs in the upstairs bath wired to a gfci outlet in the garage. Lemme tell you how much fun THAT was to figure out the first time I popped the circuit...

My dads "retirement community" home is wired with a separate gfci for every outlet. There are no standard plugs in the house. Never seen that before either.
 
Soon after we moved in, the outlets in one of the bathrooms weren't working. I was about to give up and call an electrician, when I realized that they were tied to the GFI plugs in the other bathroom! So when the GFI was triggered in bathroom 1, which happens frequently, the plugs went out in bathroom 2.

Guess electricians make mistakes too.

That might be code. We had that in all our homes the past 20 years. the GFIs would trip in one bathroom and all the bathrooms go dead.
 
Al...very common for a house to be wired with both bathrooms, a bathroom and a kitchen, or bathroom/kitchen and outdoor plugs all back to one gfci.

I'm sure theres a reason for this, other than saving a buck fifty an outlet.

My house has two of the three bathrooms, the garage outlets, and the outlet on the back of the house all wired to a single gfci in the laundry room. My old mcmansion had all the plugs in the upstairs bath wired to a gfci outlet in the garage. Lemme tell you how much fun THAT was to figure out the first time I popped the circuit...

My dads "retirement community" home is wired with a separate gfci for every outlet. There are no standard plugs in the house. Never seen that before either.

We found this out at our present home when a curling iron + hair dryer in one bathroom combined load with a space heater in the other bathroom. Poof! Circuit breaker took out both bathrooms. We're now careful to coordinate the use of high watt devices in the bathrooms.
 
Saw a bumper sticker on a truck at the gas station today-

"Wiring is not a hobby- Hire a licensed Electrician"

The truck was a 2008 F-350 XLT Crew Cab 4 x 4 Powerstroke Diesel Dually with custom wheels, a lift kit, etc, pulling a new 30' hi-performance offshore-type speedboat with twin V-8 engines.... matching custom paint jobs on both. High-maintenance surgically enhanced blondes in the front and back seats...

I'd study Trombone Al's diagrams a little longer before I called this guy in.
 

Latest posts

Back
Top Bottom