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Light switches that do not affect the power flow

JimmyTheMonkey

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Aug 14, 2013
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128
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Atlanta, GA
So I know this is a bit of a basic question, but I am positive someone here can shed some light (ha!)

60 year old garage with original wiring throughout most of it. I have a switch box with three switches. The middle switch clearly turns on and off the majority of the lights in the garage - however the lights affected by this switch were installed right before we moved in and so I imagined this switch was replaced or "turned on," for lack of a better term.

The other two switches dont appear to do anything, however. I followed the wiring from the breaker box (also in the garage), and both switches have wiring running from the box, through the switch, and then on to other sources. The left switch has wiring running to two outlet banks, and both outlet banks are not affected by the switch in any way (I plugged in a shop vac and stereo and flipped the switch with no effect). The other switch runs to an old light point and then into the ceiling to what I think is the old ceiling light and switch. Regardless, that switch doesnt do anything either.

So, first, how is it possible that a switch has cable running through it but the switch itself has no effect on that cable. I guess there must be a way to defeat the switch portion of the switch, but then why run it through a switch in the first place? Do switches sometimes fail and then get stuck in the "on" position?

Second, I plan on adding some more outlets and lights to the garage, could there possibly be something else wrong that I am not thinking of, or could I simply add the lights, wire them to the switch box, and just replace the the current switch?

I took some pictures of the exposed box last night that looked fine but they are really blurry now, I can take more pictures tonight and post, if necessary.
 
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larry_g

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oregon
On the switch that controls the outlets, did you try every receptacle to see if only one is switched? A switched duplex outlet can have one switched receptacle and one live one in the same unit. So you have to check each and every one.

lg
no neat sig line
 

kamesama980

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Mar 28, 2013
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columbus, IN
It's conceivable that it would break internally and short or leave the contacts closed, yes.

Or, someone didn't want the outlets switched and simply moved the wires around in the box to use the half of the switch as a jumper or nutted the wires together to bypass the switch entirely.

Best way to tell would be kill the circuit, pull the cover off, make sure it's not energized, then check for continuity across the switch terminals.
 

ezzzzzzz

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Jan 25, 2012
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Are the wires actually connected to a breaker in the box? Is the breaker 'ON'? Is it possible that the breaker is bad?
 
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JimmyTheMonkey

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Location
Atlanta, GA
Are the wires actually connected to a breaker in the box? Is the breaker 'ON'? Is it possible that the breaker is bad?

The breaker works and every outlet/light that the wires are connected to works, the switches just don't seem to do anything.

It's conceivable that it would break internally and short or leave the contacts closed, yes.

Or, someone didn't want the outlets switched and simply moved the wires around in the box to use the half of the switch as a jumper or nutted the wires together to bypass the switch entirely.

Best way to tell would be kill the circuit, pull the cover off, make sure it's not energized, then check for continuity across the switch terminals.

I have not fully pulled everything out yet. I see wires going into the side of each switch, but it's possible they are old wires and the actual wiring is nutted behind the switches. Good idea. I will take everything apart this weekend and get a better look. All of the old wiring is 2-wire, so I probably should just replace it so the new outlets I am adding are grounded.
 

Thumper68

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May 16, 2013
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Duluth MN
It is possible that they used the hot feed from the outlets to feed through the switch to some other load.

You said that you followed the wire from the breaker to the outlets did it go to the switch first or to the outlets?
 
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G_P

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Central CT
On the switch that controls the outlets, did you try every receptacle to see if only one is switched? A switched duplex outlet can have one switched receptacle and one live one in the same unit. So you have to check each and every one.

lg
no neat sig line


This is what I think it is. You need to turn the switch off and then plug something into each and every outlet (top and bottom) sometimes the top is constantly on and the bottom is controlled by a switch or vise versa.

Or the switch was bypassed by wirenutting the hots together but the switch was left in place to avoid having an open hole in the cover plate.
 

eljefino

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Feb 21, 2008
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336
Maybe there used to be 1/2 an outlet that was switched but the outlet went out or some in-between homeowner thought it was broken and replaced it with a new outlet, with the shorting tabs intact, thereby backfeeding the entire switched portion of the circuit.

I'd get one of those voltage sniffers and be careful, making no assumptions before touching stuff out there.
 
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JimmyTheMonkey

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Aug 14, 2013
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Atlanta, GA
This is what I think it is. You need to turn the switch off and then plug something into each and every outlet (top and bottom) sometimes the top is constantly on and the bottom is controlled by a switch or vise versa.

Or the switch was bypassed by wirenutting the hots together but the switch was left in place to avoid having an open hole in the cover plate.

That is a good point. I have not tried every receptacle in each outlet box. I will try this tonight!

Sorry for not getting back sooner - I came down with the flu and didn't have the energy for house projects.
 
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JimmyTheMonkey

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Atlanta, GA
Thanks for the advice, everyone. I shut the power off and just traced every wire back that I could. Luckily, my garage has exposed rafters, making everything a lot easier. It appears that at one point in time, the two extra switches controlled old, no longer functioning lights in the garage and one on the front of the garage. Since the wiring was very old and distressingly corroded in many areas (it looks like Rats got to some of the wire at times, i just cut out all out and removed the old fixtures. I was a little worried that I was going to mess up another unforeseen outlet or light in the house as one of the wires disappeared behind a wall, but all is well, in the end.

I ended up moving the one working switch into a new PVC box along with a new switch I installed for a new ceiling fan to help dry the cars when they come into the garage soaking wet. Much better in the end!

Thanks for the help everyone!!

After finished:



Before work:






 

gayler

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Sep 22, 2011
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Lakin Kansas
Must be a real old switch. I've never seen one like that. I'll leave any criticizing to the pro's. Oops, I see now that that switch box is the old one you replaced.
 
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JimmyTheMonkey

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Aug 14, 2013
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Atlanta, GA
Must be a real old switch. I've never seen one like that. I'll leave any criticizing to the pro's. Oops, I see now that that switch box is the old one you replaced.

Ha!! That would be pretty scary if i spent hours fixing up the switches and it ended up looking like the "before" picture. I'm very happy with the final product. Not showroom perfect, but very utilitarian for the working garage!
 

timewarp

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Feb 24, 2008
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Location
Silverdale, WA
The 2 switches on the left side of the old box look like they are 3 way switches, they have a black, white, and red wire on them, they should be tied to other switches somewhere else in the building.
 
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