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HouseWiringQuestion -- ProllySimpleStuff... Sorry



Jan 1, 1970
Ok, hire an eletrician. That out of the way...

in my mothers older house she had added on a porch, and a room offset
from the main house. She hired uh... well, i guess you could say
people doing side jobs, they wired the room/porch on two separate
circuits. Both worked for years, but recently one started acting up.

The only change I know of is an extra single pole switch was added
next to an existing one (the single plastic box was replaced with a
double gang box). I know only what I've read in the last week in
several books sooo.. NOW there are only two cables coming in or out,
and one goes straight to a wall light that was added, meaning there
was only one (2wire?) cable coming in originally, with a black, white
and ground wire. Simple enough to wire to a single pole switch eh?
It doesn't make a difference where the white or black wire screw in
does it, top or bottom? anyway got white at top and ground to the
ground screw. Did both switches that way, even though I believe the
second switch just goes to the light and the light is not wire to
anything else, a closed circuit there.

Well crapolla neither one works, you would think ONE or the other
would work, each one is wired completely to a single cable ...

Here's the mystery to me... I use a circuit tester (with the little
neon bulb), touch black to ground = neon on
white to ground = neon on
black to white = nothing

the same thing happens in a receptacle elsewhere in the circuit.

from reading white to ground should = nothing

a symptom is... the circuit works on rare occassions for a couple days
and off for weeks, or month or more...

Is there a short somewhere, wouldn't a short flip the circuit breaker
(it doesn't flip) ? how about it being grounded early in the
circuit... say a wire became corroded in a fixture box (one box might
have gotten water in it at one time or more, unsure though) Would that
cause the entire circuit to fail?

Sorry to ask such a question here, but don't know where else.. any

Thanks for any help you can give



Jan 1, 1970
Tom Thanks for taking the time to answer.

Going into the panel box isn't something I'm looking forward to. It's
a little more complicated then changing a switch/receptacle/etc.,
which is all I was geared up for.

Prior to that drastic(for me) step, I'm going to pull every outlet and
see what's to see. Read somewhere about corroded or dirty contacts
might cause a ground? There are a couple fixtures on the porch, who
knows, the circuit has been going off and on for the better part of a
year so and extra week or two preparation won't hurt.

Again thanks, gives me another place to look.


Grumpy OM

Jan 1, 1970

I had a similar problem. Traced it to an outlet in the bathroom
where my wife plugs in her hair dryer. First check outlets where high
current devices have been used. Since this is an older house also note
if aluminum wiring is used. This can cause all sorts of trouble.



Jan 1, 1970
my mother...hired...people doing side jobs...
Check the neutral bar,
the place where all the whites are connected,
and see if one is loose.

This is how your house is wired
(starting from the transformer on the pole).

breaker individual switch
(2 poles) breaker
___ ___ 110V (black) /
______ __o o________o o__________________o/ ____ switched 110V <----
) || ( . |
) || ( . |
) || ( . neutral for upper (zero volts) white |
) || ( . _________________________________________ |
1100V ) || ( . |
) || ( . | neutral for lower (zero volts) white
) || (_________|________________________________________ 220V
) || ( . |
) || ( . | ground (at the panel) green
) || ( . __|__ (REALLY zero volts) |
) || ( . ___ |
) || ( . _ |
) || ( ___ ___ 110V(black) / |
______) || (__o o________o o__________________o/ ____ switched 110V <----
From black to ground is 110V.
From black to white is 110V.
From white to green better be no more than 3V.

Highly unlikely, but bad contact
might cause a voltage drop under high current
(> 3V white-to-green)

Wire colors at a switch don't mean much.
The jack-leg guys might have done them either direction.
(I wish the National Electric Code
specified a color for switched 110V,
other than black or white.)

Remember, the mark of a wise man
is knowing when to call in a pro.

Jeff (also a grumpy old man)