Light switch stopped working.


  #1  
Old 07-16-20, 09:54 AM
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Light switch stopped working.

After installing a caseta smart switch the overhead light in the TV room was working just fine. Days later the electricity went out. When I turned it back on everything was fine in the house. That night, when I tried to turn on the overhead light in the TV room, there was no response from the switch. The following day I tried to replace the switch with the old one (just case something went bad with the new Caseta lutron switch) but it turns out that now I have no electricity at all in the black wire (I used one of those pens that turns a red light on).

I did try to reset all the fuses (I do not know which specific fuse takes care of that line) and the rest of the house is just fine, just that light switch. Coming out of the box is just the usual 3 cables: black, white and copper.

I really do not know what else to do or to check .. can you please help me? than you. Chris.
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Old 07-16-20, 12:53 PM
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There should not be power in the black wire. The white wire should be hot.
 
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Old 07-16-20, 01:33 PM
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Get rid of that tester, you need a voltmeter, the bulb is a known good bulb? with a meter test between White and ground, and Black and ground, nothing happens when you splice white and black together?
Geo
 
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Old 07-16-20, 04:05 PM
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I checked and and there is no power in any of the wires.
 
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Old 07-16-20, 04:35 PM
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Hi,

I used a voltmeter instead (but yes, the red light works on the "pencil") and I attached a picture. Basically, when the voltmeter was set to AC and Volts with the red side touching the white wire and the black side of the voltmeter touching the black wire the result was 0.173 (I enclosed a picture for you to see).

Again, thank you in advance for any tips you can give me.
Chris.

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Old 07-16-20, 05:51 PM
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the switch is not the problem. You have an open connection somewhere else. Any chance there might be a GFCI that is tripped?
 
  #7  
Old 07-16-20, 07:16 PM
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Welcome to the forums.

That is a switch loop. The power there should come down on the white and return switched on the black wire. You'll need to remove your light and check there for power IF that light is the only device that is dead.
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Old 07-17-20, 09:29 AM
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ok, let me check every GFI switch I can find.
 
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Old 07-17-20, 09:43 AM
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I see, the problem then may be an outlet from which the cables come to the light switch .. let me see if any electrical outlets are tripped.
 
  #10  
Old 07-17-20, 10:10 AM
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The cable doesn't go to the light switch. You have a switch loop. the cable goes to the light.
 
  #11  
Old 07-17-20, 10:31 AM
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Joed, I checked all my electrical outlets and GFI switches anywhere in the house and everything works. As matter of fact, every light switch works every where in the house .. it is just thins light switch.

So you say that I have a switch loop .. i googled that and I am sorry but do not know what to do to fix it. Can you tell me please.

Thank you,
Chris.

 
  #12  
Old 07-17-20, 10:43 AM
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Please refer back to post 7.
 
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Old 07-17-20, 12:21 PM
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Solved !!!

Well, there is it, it got fixed. Sorry this took so long, I have never seen a "switch loop" and never knew that the white wire can be the hot wire. So I followed step 7, took apart the light fixture and replaced its transformer and now it works!!. Thank you because this has been going on for weeks and I was so lost; you guys made it happen.
Thank you.
Chris.
 
  #14  
Old 07-17-20, 12:27 PM
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Good job.

Technically when there is a switch loop used..... the white wire is supposed to be taped or colored something other than white to signify that it is not neutral. Red or blue are two useful colors to use.
 
 

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