Light circuit lost voltage

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  #1  
Old 11-17-15, 12:30 PM
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Light circuit lost voltage

I have a motion detector light at the back of my house. It has not worked in years. At one time I remember it coming on but not anymore. I can not find a switch in the house for it and so I assume it is direct wired. I want to install a new light now. I removed the old light and checked the voltage. It reads 1.5 volts. WTH?!?!
Any idea whats going on here? All the other things on the same circuit work fine.
 
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Old 11-17-15, 01:10 PM
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Just do double check do you have any mystery switches which you don't know what they do? Does the light have just a single 2-conductor cable. Did you measure both hot to ground and hot to neutral? Is this light on a wall with the inside finished or an unfinished attic gable?
 
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Old 11-17-15, 01:19 PM
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There is a ground wire coming out of the wall which is attached to the crossbar that the light screws to. The other 2 wires coming out of the wall were attached to the fixture, and they are black and white. These measure 1.5 volts.
We do have a mystery switch but it has no effect. I will check voltage again tomorrow with this switch in the other direction. Either way, 1.5 volts with a switch on or off is a defect, isn't it?
 
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Old 11-17-15, 01:27 PM
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Probably a defect in your meter or the way you're using it. What you're seeing is likely a phantom voltage reading. If you measure the voltage with a load in parallel it will read zero. An analog meter or neon bulb tester makes this more obvious than a consumer-grade digital meter.
 
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Old 11-17-15, 02:15 PM
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There is a ground wire coming out of the wall
What is the voltage between ground and black.
 
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Old 11-18-15, 11:57 AM
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As I said, black to white measures 1.5 v. I just went out to check measurements to ground. White to ground measures 155v and black to ground measures 1.5v. This is really rediculous because it should be a 110v circuit.

As far as I can tell, all other items on this circuit are working fine.
 
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Old 11-18-15, 12:01 PM
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You have lost your neutral connection. White/neutral to ground should be 0v.
 
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Old 11-18-15, 12:03 PM
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Where is the 155v on the white/ground coming from?
 
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