Confused on Switch Wiring


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Old 01-16-18, 08:33 AM
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Confused on Switch Wiring

Hello all, I am in the beginning stages of installing a new outdoor light that has never been used since I moved in. I am familiar with majority of the circuits in the house except this one.

I have one wire with two power wires going to each side of my switch a white thatís hot and a black thatís hot when I test them with a pen tester. I then have one wire going to the light fixture with a black and white. I assume that the power is coming from a junction box that I havenít found yet, but still donít understand why both sides of the switch would be hot?

I turn the switch to the on position and it kills power to the light. I turn it to the off position and it restores power to the light. My next steps are removing the wires from the switch and testing them independently to ensure they are both hot and the switch isnít making them both hot. And also trying to find the circuit that it is fed off of.

I want to install a smart switch that needs a dedicated common and not sure how I am going to do this. I am adding pics to take a look at.

Thanks!
 
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Old 01-16-18, 08:45 AM
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You have what is called a switch loop. However, you should have at least two 14/2 cables in the ceiling box. One for a feed and the other for the switch. You're saying black and white are both hot even with the switch disconnected? This wouldn't be correct and would mean something isn't wired properly (and possibly why it has never worked). Is there a box in the ceiling?

BTW, a multi-meter would be a better troubleshooting tool.
 
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Old 01-16-18, 08:52 AM
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I have one wire with two power wires going to each side of my switch a white that’s hot and a black that’s hot when I test them with a pen tester.
I'm going to stick with just this one sentence for now. For clarification, a wire is a piece of copper or group of them stranded together and covered by insulation, other than a bare ground wire. Multiple wires inside another sheath are called a cable. So, it sounds like you have a cable with what you're calling power wires but the term 'power wire' is not standard - do you mean these are constant hot wires? Are these the white and black wires you mention? Finally, a non-contact tester is not the right tool for this job, a multi-meter should be used (you can get change back from a $20 bill for a decent analog meter).
 
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Old 01-16-18, 09:31 AM
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I turn the switch to the on position and it kills power to the light. I turn it to the off position and it restores power to the light.
I missed this part. So it sounds like everything is normal. There should be two cables inside the ceiling box correct?

Both wires going to the switch will be hot when the switch is closed. This is normal.
 
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Old 01-16-18, 10:01 AM
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mossman, read it again:
I turn the switch to the on position and it kills power to the light. I turn it to the off position and it restores power to the light.
Switch ON--kills power, switch OFF restores power! I know what you are saying but it sounds like the switch is wired backwards (possibly switching the neutral).
 
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Old 01-16-18, 10:28 AM
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Regardless if it is switching the hot or the neutral, closing the switch (turning it "ON") should not turn the light off. I would remove the switch to take it out of the equation. You can touch the wires together or wire nut them temporarily to simulate a switch.

Turning the switch off would be equivalent to cutting the wires and leaving them disconnected. The light working with the two wires disconnected makes no sense at all. The only thing I can think of that would cause this (theoretically speaking) is the switch shorting the hot to neutral, in which case sparks would fly, breaker would trip, wires would melt.

Are we talking about an actual light fixture here or are you using your pen tester to detect voltage?
 
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Old 01-16-18, 07:20 PM
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I am just getting on and seeing all the replies. I thought I would get a notification, but I didn’t. Thank you all!

I do have a multi-meter and had all intentions of testing it tomorrow. I just figured I would throw this out there in the meantime. I completely understand the two 14/2 cables for the feed and the other for the switch. And this is where my confusion came in. There was one 14/2 cable coming to the switch and one 14/2 cable at the light. Something that I have not seen before. However, the switch did turn power on and off to the light.

The first thing I am doing in the morning is using the multi-meter to see exactly where the hot wires are and if the others are neutral.
 

Last edited by PJmax; 01-16-18 at 08:20 PM. Reason: subscribed to thread
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Old 01-16-18, 08:21 PM
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When in "Go Advanced" editor page...... go to the bottom of the page and you'll see subscribe to thread. I checked that for you and you will now receive instant email notification. It needs to be turned on for every thread you want to be notified.
 
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Old 01-17-18, 05:12 AM
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Originally Posted by PJmax
When in "Go Advanced" editor page...... go to the bottom of the page and you'll see subscribe to thread. I checked that for you and you will now receive instant email notification. It needs to be turned on for every thread you want to be notified.
Thank you very much for setting that up. I thought I originally did it, but probably missed something.
 
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Old 01-17-18, 07:41 AM
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There was one 14/2 cable coming to the switch and one 14/2 cable at the light. Something that I have not seen before. However, the switch did turn power on and off to the light.
If that's the case, then there's a junction box somewhere where the switch loop meets the switch lead for the light. If you're simply replacing the switch and light fixture, then there's really no reason to track this down, unless you absolutely want to.
 
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Old 01-17-18, 10:46 AM
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Originally Posted by mossman
If that's the case, then there's a junction box somewhere where the switch loop meets the switch lead for the light. If you're simply replacing the switch and light fixture, then there's really no reason to track this down, unless you absolutely want to.
That was thoughts exactly until the Wemo switch needed a dedicated Neutral. So this is my findings and solution (if the solution makes sense).

Wiring is fine, just more of how they did it in the late 70's I guess.

Breaker On (Breaker was on a 20a circuit that is garage outlets and that one outside light garage light)

At Light

Hot/Ground- 120
Neutral/Ground- Nothing

At Switch

Hot/Ground- 120
Neutral/Ground- Nothing


Separated wires at switch and Hot/Ground was still 120, and nothing at light. Tied Hot/Neutral back together and I had constant power at the light. Which shows me that the switch was working properly before removal and that is where my power is coming in.

Solution:

- I run a brand new 14/3 cable from light fixture to switch.

- I tie the old black/whitel together and put them in the back of the switch box (this pretty much eliminates the switch for now).

- Whites (old and new 14/3) at fixture goes into white on outdoor light and ties back into white on Wemo switch.

- Black (old) ties into Black (new 14/3) at light and ties back into the B-Line on the Wemo.

- Red (new 14/3) goes with the black on the light itself and ties back into the B-Load of the Wemo.

- And all ground will still stay together.


I believe this will still be up to code and operate properly. Thoughts?
 
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Old 01-17-18, 10:52 AM
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Separated wires at switch and Hot/Ground was still 120, and nothing at light. Tied Hot/Neutral back together and I had constant power at the light. Which shows me that the switch was working properly before removal and that is where my power is coming in.
You said earlier that when the switch was "on", the light was off, and vice versa. Switch "on" means wires connected. Now you with wires connected the light is on. That's the opposite of what you said earlier. BTW, the white in the switch box is not currently a neutral because it is wired as a switch loop. Your "power" is coming into the junction box that you have yet to locate, and the 14/2 from the fixture and 14/2 from the switch both go to said junction box.


I think I'm following you for the most part (a diagram would be nice), but am a little confused--are you installing two lights? You say "fixture" and "outdoor light". Rather than connecting the black and white together in the switch box, I would locate the junction box and re-wire things to give you a hot and neutral at the switch box, then run a new 14/2 from the switch to the outdoor light.
 

Last edited by mossman; 01-17-18 at 11:35 AM.
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Old 01-17-18, 01:06 PM
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Originally Posted by mossman
You said earlier that when the switch was "on", the light was off, and vice versa. Switch "on" means wires connected. Now you with wires connected the light is on. That's the opposite of what you said earlier. BTW, the white in the switch box is not currently a neutral because it is wired as a switch loop. Your "power" is coming into the junction box that you have yet to locate, and the 14/2 from the fixture and 14/2 from the switch both go to said junction box.


I think I'm following you for the most part (a diagram would be nice), but am a little confused--are you installing two lights? You say "fixture" and "outdoor light". Rather than connecting the black and white together in the switch box, I would locate the junction box and re-wire things to give you a hot and neutral at the switch box, then run a new 14/2 from the switch to the outdoor light.
You are absolutely correct, I did say that. And I may have misspoken before I had a chance to actually test using the multi-meter. I think what you are referring to was nothing more than the switch being upside down. Once I tested everything I figured out everything was operating properly. I do indeed have the switch loop.

I would love to find the junction box and make my life so much easier, but I would have to rip down my entire garage to find it. It is either in the eave that is not accessible or somewhere in the framing of the Garage.

I will include probably the worst hand drawn picture you have ever witnessed, so please donít yell at me. Haha.
 
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Old 01-17-18, 01:17 PM
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Perhaps not the best way, but it will work how you show it.
 
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Old 01-17-18, 01:42 PM
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I understand about the white in the switch box not currently acting as the neutral. That is what I am trying to gain from running the new wire. Most times my electrical lingo is lacking and my mind is moving faster than my keyboard. I am installing one new light replacing the one there. When I said fixture or light I meant the same thing. Thanks!
 
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Old 01-17-18, 01:48 PM
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Originally Posted by mossman
Perhaps not the best way, but it will work how you show it.
Thank you did all of your input, I appreciate it.
 
 

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