Tough trouble call - dead light circuit

[ramsy]

First trouble call I had to walk away from.

Relatively new NM cable home, no crawl space between floors, customer says lights stopped working one day. Can anyone come up with a new plan or procedure for me to try?

Solenoid tester results:
1) Dead wires going to light switches x 2. (opposite side of same wall)
2) All 120v breakers at panel were energized, nothing tripped.
3) All receptacles had power, along same wall as switches.
4) Switch leg continuity to receptacle ground. (OK thru bulb filaments)?

Fox & hound results:
1) Tone shows same wires on both switches. (boxes not back to back)
2) Tone follows (H,N) circuit behind drywall in several directions.
3) No loose wires in boxes or upstairs switches, traced with fox & hound.
4) Same tone not present at de-energized panel, neither Hot, G, or Neutral.

I told customer cutting into walls to re-feed the lights is a last resort.

 

[peter d]

Is it a tract home wired by pieceworkers? The first thing I would look for is a bad "stabbed in" receptacle. These are notorious for intermittent continuity.

 

[BackInTheHabit]

What do the switches control,or what lights do they control?

Are the switches single pole or three way?

If they are three way, how are they wired?

Peter d is correct in that there is probably a back stabbed wire, probably a neutral, that is loose.

 

[kjw444]

Had a similar problem where the customer all of a sudden lost power to his lake water pump. Three different people tried fixing the problem to no avail. The problem was, there was a switch covered by shelves with a plastic backing and all of the jarring around caused the switch to open. Is your switch a three way and possibly the same problem where it could be covered up and knocked to the middle position? Sometimes we overlook the simplest problems.

 

[mdshunk]

I'm voting for a bad backstab.

 

[ramsy]

What do the switches control,or what lights do they control?

Are the switches single pole or three way?

If they are three way, how are they wired?

Peter d is correct in that there is probably a back stabbed wire, probably a neutral, that is loose.

Bad porch light circuit was caused by loose back-stabbed switch, no EGC either, with grounds Ferrel crimped in same box.

Removing wirenuts in these switch boxes was impressive. Pre-twisted with a drill motor, wires did not need nuts to stay together.

The dead circuit for both SP switches in question control can lights in living & dining rooms; everything else in house works fine.

When I traced tone upstairs, and took apart switch boxes, I found more back stabbed switches, including 3 ways; all of which passed visual and tug test.

But, doing so de-energized with fox & hound does not find loose ends, everything rings with the same tone, and all the lights upstairs worked fine.

Should I turn everything on, wear my rubber gloves, and wiggle those stabbed switches upstairs with a tic tracer?

 

[ramsy]

Is it a tract home wired by pieceworkers? The first thing I would look for is a bad "stabbed in" receptacle. These are notorious for intermittent continuity.

Yes, tract homes. There's no tone from switch wiring to any receptacles.

Is it possible, by putting the tone on nearby receptacles first, the switches will prove to be upstream from the receptacles?

 

[BackInTheHabit]

The dead circuit for both SP switches in question control can lights in living & dining rooms; everything else in house works fine.

Since you mentioned can lights:

How many can lights are there on the circuit?

Are the can lights rated for direct contact with insuation? Check this by looking inside the can near the socket. The can lights may have a thermal overload. If too near insualtion they may be overheating. Some builders insulate the floor joists between each floor.

 

[ramsy]

About 6 cans total. When I go back this weekend, I will check the cans for a thermal overload. May even pull a few down and check for loose wires.

 

[glene77is]

Then, maybe suggest the HO install compact flourescent bulbs
to reduce heat problems.

 

[quogueelectric]

At the risk of repeating myself Amprobe 2005 will find it to within a few inches in the wall. Barring that first see if you have continuity from neutral to ground. Homeowners lie and it might just be a burried box that was never spliced out because it was burried. Look for code compliance in the room for receptacles placement like the 12 ft thing and bellies in the walls. I am going for burried box for 200. Edit to say that I ring neutral/ground to determine if it is landed in a panel or it is a cut/broken wire.

 

[ramsy]

Went back today for more.

1) 30W bulbs & switches work perfect when fed from receptacle extension cord.
2) Dead wire originally feeds switches from wall.
3) When EGC & Neutral are not connected to Fox & hound, the dead hot wire fades away on two seperate & perpendicular walls, going in oposite directions.
4) Customer wants me to cut wall & feed switches from receptacle. This may eventually risk a bolted fault, if recep. is on oposite phase.

Can anybody nearby rent me a real wire tracer?
Will provide deposit & colladeral.

 

[ramsy]

--Mod Squad-- Please delete duplicate

 

[Brady Electric]

dead light circuit

dead light circuit

I bought a Ideal tracer set from Rexel two years ago for only $500 and it works great. It was $900 at other supply houses so you have to shop around
It will follow wires into the wall and trace breaks or shorts
You can also find wires in the ground
After all these years I do it the easy way
Check a meter book and look for Ideal testers
Good luck Semper Fi Buddy

 

[LarryFine]

Roger, try the wiggy-and-extension cord test to determine whether you're missing the hot, the neutral, or both.

 

[ramsy]

Check a meter book and look for Ideal testers..

How about a Brady Pathfinder 12-A for US $3.00

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260265918643&ssPageName=STRK:MEWA:IT&ih=016

 

[ramsy]

Roger, try the wiggy-and-extension cord test to determine whether you're missing the hot, the neutral, or both.

Larry, I originally learned that trick from you. Last week it helped me check out an outlet with open neutral. The final step was trying another GFCI, which worked fine. Home center replaced defective device.

 

[ramsy]

Those can light conductors looked like #12 to me. So, if eBay doesn't give me a cheep tool, I might just feed those cans from the receptacle circuit, replaced with an AFCI breaker.