# Stumped! Continuity but no voltage.



## Jlarson (Jun 28, 2009)

hometodos said:


> Any help would be appreciated... Today I had a customer who's stairway night lights were out (120 volt). I checked the photo sensor outside and it was fine. The photo sensor feeds two lights over the garage doorway before the line runs into the house and to the stairs.
> 
> I put a tone generator on the line at the stairs (black only) and got a strong signal at the photo sensor. Same for the neutral.
> 
> ...


2 volts from what to what? Ungrounded to grounded, ungrounded to grounding?


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## erics37 (May 7, 2009)

hometodos said:


> I'm stumped. Any ideas? Anyone? Thanks!


Did you physically open up the 2nd garage light and check out the connection feeding in to the stairs?

A toner has it's place but I prefer physically checking splices if part of a circuit is mysteriously not working after a certain point.


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## BCSparkyGirl (Aug 20, 2009)

really, silly question, but sometimes it's the right one.....did you check the light bulb itself? Or flip the breaker? Or that gfi hidden in the garage for some weird reason?


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## 480sparky (Sep 20, 2007)

Time to call an electrician.


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## hometodos (Oct 7, 2010)

Yes, erics37, I checked both lights over the garage and the wiring is fine. 

Answer to BCSparkyGirl: My tests at the stairs were on the line feeding it, with the chain of lights diconnected. (they all work fine with another power source). No GFCI on this circuit. Breaker not tripped.

Answer to Jlarson: 2 volts AC black/white wires


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## MDShunk (Jan 7, 2007)

Your initial assumptions as completely incorrect. You state, "continuity but no voltage", yet you checked continuity with a toner? Give me a break. :laughing: Get out an extension cord or roll of THHN and check with a meter. Something's broke somewhere.


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## hometodos (Oct 7, 2010)

Ok MDShunk. I'll do that. thanks.


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## Jlarson (Jun 28, 2009)

hometodos said:


> Answer to Jlarson: 2 volts AC black/white wires


Did ya check from hot to ground?



MDShunk said:


> You state, "continuity but no voltage", yet you checked continuity with a toner? Give me a break.


Yeah, not my first choice either. :no:


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## Marshall175 (May 23, 2009)

480sparky said:


> Time to call an electrician.


gonna have to go with 480 on this one....

a toner???????


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## Split Bolt (Aug 30, 2010)

Tone generators can actually be wonderful troubleshooting tools in some situations! They work perfectly with romex. I've had mine lead me to tripped GFI receptacles in 2 different basements. In both cases, the homeowner had no idea that those receptacles even existed. One was in a linen closet behind some towels and another in an unfinished area behind a bunch of boxes!:thumbsup:


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## electricalperson (Jan 11, 2008)

broken wire, or bad splice. :thumbup:


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## I_get_shocked (Apr 6, 2009)

hometodos said:


> Any help would be appreciated... Today I had a customer who's stairway night lights were out (120 volt). I checked the photo sensor outside and it was fine. The photo sensor feeds two lights over the garage doorway before the line runs into the house and to the stairs.
> 
> I put a tone generator on the line at the stairs (black only) and got a strong signal at the photo sensor. Same for the neutral.
> 
> ...


Begin by switching to low impedance or a solenoid meter. Then once you discover you have 0 volts, switch to continuity and find the break


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## LARMGUY (Aug 22, 2010)

MDShunk said:


> Your initial assumptions as completely incorrect. You state, "continuity but no voltage", yet you checked continuity with a toner? Give me a break. :laughing: Get out an extension cord or roll of THHN and check with a meter. Something's broke somewhere.


Toners only work on normally open wires, short them together and the tone stops.


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