The infamous mysterious third switch


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Old 12-22-14, 03:25 PM
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The infamous mysterious third switch

Good evening everyone. I am quite sure this has been addressed but am here to ask for the guru's help. I am an Aircraft Technician so am aware of the basics of electricity. Right now I have 3 switches. 1 controls the ceiling fan, another controls the light kit to the ceiling fan. The third controls..... The configuration of the first two switches mentioned above are the standard white/black ground configuration. When I hook my multimeter up to them they work as they should. The third switch has a red wire going to it with a black and ground. This red wire makes the switch a constant hot. No matter what position the switch is in, I still have voltage. Thinking that perhaps this switch went to an outlet, I disconnected it from the switch and checked all my outlets. They still work. I am assuming I am going to need to pull power off the wall and see where the white wire is spliced in. (It's a rat's nest back there).
My original reasoning for going in to the switch box was that I wanted to add an additional outlet in the room and have it controlled by that switch. Obviously if I was to wire in an outlet to that switch as it is currently configured then is it safe to assume that the switch would have no bearing on power going to and from the outlet due to the red wire attached. I felt comfortable doing this job and the red wire threw a monkey wrench in to the plan. Any assistance would be greatly appreciated.
Thank you.
 
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Old 12-22-14, 03:30 PM
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White/black/ground is not a typical switch configuration and would indicate a switch loop.

There is just the one black and the one red on the third switch? Disconnect both and you should find only one of them is hot.
 
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Old 12-22-14, 03:30 PM
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How are you measuring voltage at the switch with the red and black? Where is the white wire associated with this cable? Capped off, possibly? You should be measuring from red to ground and black to ground. There are no white wires connected to this switch?
 
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Old 12-22-14, 03:45 PM
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3rd switch configuration

Name:  switch.jpg
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The third switch has the red going in at the bottom. In order to check voltage I am going from ground to each pole. On a normal switch in the off position I get .053v. On I get about 122v. However with the third switch with the red wire it does not matter what position the switch is in. I haven't gotten to the stage of finding the white wire yet. Was just wondering what I do with the red once I find the white wire.
Thanks for all the replies so far.
 
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Old 12-22-14, 03:49 PM
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Chandler with the red disconnected, I get no voltage to the switch whatsoever.
 
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Old 12-22-14, 03:51 PM
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It looks as if you have a remarked white wire on that switch, just colored red on the end, as it should be. That accounts for the white wire we couldn't find. You have a switch loop. Remove the wires from the switch and measure the voltage. You could have a soft switch, meaning it doesn't completely open the circuit when it is turned off. If you find that you have 120 volts on one wire to ground and phantom voltage on the other wire to ground, replace the switch and see what it controls. You may find that only one half of a receptacle nearest this switch is actually operated by the switch, with the other half hot all the time.

Edit: You posted while I was slowly typing. Do you have 120 volts to the red wire?
 
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Old 12-22-14, 03:59 PM
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Chandler yes. When I disconnected the Red wire and went from ground to the red wire by itself I had 120. With the red wire taken away the switch had no voltage. Also the Red Wire is marked all the way up to the sheething if that makes sense.
 
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Old 12-22-14, 04:10 PM
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Is there a white wire in the sheath? normally only the end of the white wire is marked another color to distinguish it as a loop wire, not the whole wire to the sheath. I would change the switch at this point and check for switching at your receptacles, both top and bottom.
 
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Old 12-22-14, 04:27 PM
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Thanks for putting up with me Chandler lol. I posted another picture. The white wire seems to be spliced together with the other wires and capped off with the yellow wire cap that is in the picture.

Okay so the picture won't upload :/ I traced the wire harness that has the red wire and the white wire is capped off with other white wires. All the other wire harnesses have just a black white & Ground going to the other two switches. I could swap switches and see what it does but would wait until tomorrow when I have daylight to do so. The breaker is funky to where it takes out 1/2 the house to kill power going to those switches.
 
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Old 12-22-14, 04:37 PM
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No problem. Let us know about your investigation after you change switches.
 
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Old 12-22-14, 06:53 PM
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Note: You have back stab connections on the switch. They should not be used because they are less reliable. Use the screws.
 
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Old 12-23-14, 11:51 AM
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The wire shown on the switch picture is a red that has been painted over.

I suspect someone changed out a receptacle that was formerly switched and did not break the tab on the brass side. Do you have a receptacle with a red on the brass side?
 
 

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