Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

Terry, has he been able to determine if he has a hot leg and a neutral leg?



"Terry" wrote in message
...
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

You can find out what I know by reading his comments to this thread

http://groups.google.com/group/alt.h...0356a9a4a064a6

He says no wire is hot at any box, and the light has never worked. He
is using an inductance pocket tester. I just learned he has phoned
the wires out in the past with a continuity tester.


On Fri, 1 Feb 2008 14:20:04 -0500, "RBM" wrote:

Terry, has he been able to determine if he has a hot leg and a neutral leg?



"Terry" wrote in message
.. .
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

Under the circumstances, I would abandon the circuit and run new cables to
each location


"Terry" wrote in message
...
You can find out what I know by reading his comments to this thread

http://groups.google.com/group/alt.h...0356a9a4a064a6

He says no wire is hot at any box, and the light has never worked. He
is using an inductance pocket tester. I just learned he has phoned
the wires out in the past with a continuity tester.


On Fri, 1 Feb 2008 14:20:04 -0500, "RBM" wrote:

Terry, has he been able to determine if he has a hot leg and a neutral
leg?



"Terry" wrote in message
. ..
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

"Terry" wrote in message
...
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

You seem to have it figured correctly. From the postings, I am not sure
whether the OP is missing a hot feed to one of the switches or whether he is
missing a neutral feed to the light. These can be verified by connecting a
long wire to a hot or neutral in a known working circuit and testing for
power between the extension wire and the wires in the problem area.

One common problem with electrical troubleshooting for me is that people
tend to say they do or do not have power at or on a certain wire. Power
never is present at one wire, only between two wires and you need to know
which two wires are being checked. And, of course, using a DVM instead of a
test light just confuses the issue even more.

Don Young

On Feb 1, 10:45�pm, "Don Young" wrote:
"Terry" wrote in message

...



Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. �I am assuming that at one time it
worked with what he has. �(knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. �That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. �Maybe you will have something
similar and can tell where the red wire is going.

You seem to have it figured correctly. From the postings, I am not sure
whether the OP is missing a hot feed to one of the switches or whether he is
missing a neutral feed to the light. These can be verified by connecting a
long wire to a hot or neutral in a known working circuit and testing for
power between the extension wire and the wires in the problem area.

One common problem with electrical troubleshooting for me is that people
tend to say they do or do not have power at or on a certain wire. Power
never is present at one wire, only between two wires and you need to know
which two wires are being checked. And, of course, using a DVM instead of a
test light just confuses the issue even more.

Don Young- Hide quoted text -

- Show quoted text -

just replace all the wiring, running a new line back to the breaker box

Thanks Terry for starting this thread.

I'll have to check the various suggestions out a little more on Tuesday.
Between now
and then I won't be home while it's daylight outside, and I want to be able
to see everything with and without the power on, and without having to use a
flashlight.

I went into the attic this morning, and part of the floor is already up from
when I was working on it before. But I have to take one more board up to
access directly above the light fixture, and I didn't have time to do that
today.

I have a hunch that I'm going to end up doing as some have suggested --
start over and run a whole new circuit. But, since it's a puzzle right now,
I want to get better access to the light fixture from the attic above, and
try to see if I can find a solution to the puzzle.

"Terry" wrote in message
...
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

Yeah I think a whole new circuit sounds best too.

To run a new circuit, you may still have to remove the same boards you
are removing now, though.

You might get lucky and find an easy fix. How have you been living?




On Sat, 2 Feb 2008 19:15:45 -0500, "BETA-33" wrote:

Thanks Terry for starting this thread.

I'll have to check the various suggestions out a little more on Tuesday.
Between now
and then I won't be home while it's daylight outside, and I want to be able
to see everything with and without the power on, and without having to use a
flashlight.

I went into the attic this morning, and part of the floor is already up from
when I was working on it before. But I have to take one more board up to
access directly above the light fixture, and I didn't have time to do that
today.

I have a hunch that I'm going to end up doing as some have suggested --
start over and run a whole new circuit. But, since it's a puzzle right now,
I want to get better access to the light fixture from the attic above, and
try to see if I can find a solution to the puzzle.

"Terry" wrote in message
.. .
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. I am assuming that at one time it
worked with what he has. (knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. Maybe you will have something
similar and can tell where the red wire is going.

call your homeowners insurance company see if they cover K&T wiring...
it might bring a visit by the company but thats better than finding
out after a fire

On Feb 2, 9:36*pm, " wrote:
call your homeowners insurance company see if they cover K&T wiring...
it might bring a visit by the company but thats better than finding
out after a fire

My homeowner's insurance company already knows I have knob and tube
wiring. It was listed on my application for insurance.

wrote:
call your homeowners insurance company see if they cover K&T wiring...
....

If they wrote the policy, they cover it...quit the d---'d FUD crap.

--

On Feb 3, 12:32�pm, dpb wrote:
wrote:
call your homeowners insurance company see if they cover K&T wiring...

...

If they wrote the policy, they cover it...quit the d---'d FUD crap.

--

today insurance companies go out of their way to not pay off, and some
people dont inform their insurers of risks till a fire occurs, then
insurance researches the owners activities, and occasionally doesnt pay

(From Beta-33,34,35 -- from a different computer using Google Groups -
yuck)

This probably doesn't help, but when I did the continuity check a long
time
ago, this is what I found:

I tested for continuity with all wires disconnected at both 3-way
switches
and with the hallway lightbulb not in the socket.

At the 3-way switch at the bottom of the steps, I numbered the 3 wires
as 1,
2, and 3.

At the 3-way switch at the top of the stairs, I found wires with
continuity
with two of the downstairs wires, and numbered them as 1 and 2 (the
wires
they connect with downstairs). I numbered the third wire on the
upstairs
3-way as number 4.

At the hallway light, I numbered the wires as 3 and 4. Number 3 has
continuity with number 3 on the downstairs 3-way switch, and number 4
has
continuity with number 4 on the upstairs 3-way switch.


On Feb 2, 7:48*pm, Terry wrote:
Yeah I think a whole new circuit sounds best too.

To run a new circuit, you may still have to remove the same boards you
are removing now, though.

You might get lucky and find an easy fix. * How have you been living?




On Sat, 2 Feb 2008 19:15:45 -0500, "BETA-33" wrote:
Thanks Terry for starting this thread.

I'll have to check the various suggestions out a little more on Tuesday.
Between now
and then I won't be home while it's daylight outside, and I want to be able
to see everything with and without the power on, and without having to use a
flashlight.

I went into the attic this morning, and part of the floor is already up from
when I was working on it before. *But I have to take one more board up to
access directly above the light fixture, and I didn't have time to do that
today.

I have a hunch that I'm going to end up doing as some have suggested -- *
start over and run a whole new circuit. *But, since it's a puzzle right now,
I want to get better access to the light fixture from the attic above, and
try to see if I can find a solution to the puzzle.

"Terry" wrote in message
.. .
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. *I am assuming that at one time it
worked with what he has. *(knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. *That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. *Maybe you will have something
similar and can tell where the red wire is going.- Hide quoted text -

- Show quoted text -

I was trying to find some guidelines by searching the web on the
proper way to repair knob and tube. The more I read about it, the
less confident I feel about doing anything to it.

If you can safety get a hot and a neutral to the light from somewhere
else then it sounds like the light can be fixed.

If your readings are correct, then the electrician made a mistake
wiring the lights to begin with.

This sketch sounds like what you have.

http://i26.tinypic.com/nvysuc.jpg

You should connect the (new) neutral to the screw shell of the light.
Connect the (new) hot to one of the wires going to one of the switches
and the other wire from the other switch to the light.

Maybe someone with some real K&T experience can jump in and offer a
better solution or point out a flaw in my logic.


On Sun, 3 Feb 2008 07:08:19 -0800 (PST), wrote:

(From Beta-33,34,35 -- from a different computer using Google Groups -
yuck)

This probably doesn't help, but when I did the continuity check a long
time
ago, this is what I found:

I tested for continuity with all wires disconnected at both 3-way
switches
and with the hallway lightbulb not in the socket.

At the 3-way switch at the bottom of the steps, I numbered the 3 wires
as 1,
2, and 3.

At the 3-way switch at the top of the stairs, I found wires with
continuity
with two of the downstairs wires, and numbered them as 1 and 2 (the
wires
they connect with downstairs). I numbered the third wire on the
upstairs
3-way as number 4.

At the hallway light, I numbered the wires as 3 and 4. Number 3 has
continuity with number 3 on the downstairs 3-way switch, and number 4
has
continuity with number 4 on the upstairs 3-way switch.


On Feb 2, 7:48*pm, Terry wrote:
Yeah I think a whole new circuit sounds best too.

To run a new circuit, you may still have to remove the same boards you
are removing now, though.

You might get lucky and find an easy fix. * How have you been living?




On Sat, 2 Feb 2008 19:15:45 -0500, "BETA-33" wrote:
Thanks Terry for starting this thread.

I'll have to check the various suggestions out a little more on Tuesday.
Between now
and then I won't be home while it's daylight outside, and I want to be able
to see everything with and without the power on, and without having to use a
flashlight.

I went into the attic this morning, and part of the floor is already up from
when I was working on it before. *But I have to take one more board up to
access directly above the light fixture, and I didn't have time to do that
today.

I have a hunch that I'm going to end up doing as some have suggested -- *
start over and run a whole new circuit. *But, since it's a puzzle right now,
I want to get better access to the light fixture from the attic above, and
try to see if I can find a solution to the puzzle.

"Terry" wrote in message
.. .
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. *I am assuming that at one time it
worked with what he has. *(knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. *That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. *Maybe you will have something
similar and can tell where the red wire is going.- Hide quoted text -

- Show quoted text -

On Feb 3, 12:20�pm, Terry wrote:
I was trying to find some guidelines by searching the web on the
proper way to repair knob and tube. �The more I read about it, the
less confident I feel about doing anything to it.

If you can safety get a hot and a neutral to the light from somewhere
else then it sounds like the light can be fixed.

If your readings are correct, then the electrician made a mistake
wiring the lights to begin with. �

This sketch sounds like what you have.

http://i26.tinypic.com/nvysuc.jpg

You should connect the (new) neutral to the screw shell of the light.
Connect the (new) hot to one of the wires going to one of the switches
and the other wire from the other switch to the light.

Maybe someone with some real K&T experience can jump in and offer a
better solution or point out a flaw in my logic.



On Sun, 3 Feb 2008 07:08:19 -0800 (PST), wrote:
(From Beta-33,34,35 -- from a different computer using Google Groups -
yuck)

This probably doesn't help, but when I did the continuity check a long
time
ago, this is what I found:

I tested for continuity with all wires disconnected at both 3-way
switches
and with the hallway lightbulb not in the socket.

At the 3-way switch at the bottom of the steps, I numbered the 3 wires
as 1,
2, and 3.

At the 3-way switch at the top of the stairs, I found wires with
continuity
with two of the downstairs wires, and numbered them as 1 and 2 (the
wires
they connect with downstairs). �I numbered the third wire on the
upstairs
3-way as number 4.

At the hallway light, I numbered the wires as 3 and 4. �Number 3 has
continuity with number 3 on the downstairs 3-way switch, and number 4
has
continuity with number 4 on the upstairs 3-way switch.

On Feb 2, 7:48�pm, Terry wrote:
Yeah I think a whole new circuit sounds best too.

To run a new circuit, you may still have to remove the same boards you
are removing now, though.

You might get lucky and find an easy fix. � How have you been living?


On Sat, 2 Feb 2008 19:15:45 -0500, "BETA-33" wrote:
Thanks Terry for starting this thread.

I'll have to check the various suggestions out a little more on Tuesday.
Between now
and then I won't be home while it's daylight outside, and I want to be able
to see everything with and without the power on, and without having to use a
flashlight.

I went into the attic this morning, and part of the floor is already up from
when I was working on it before. �But I have to take one more board up to
access directly above the light fixture, and I didn't have time to do that
today.

I have a hunch that I'm going to end up doing as some have suggested -- �
start over and run a whole new circuit. �But, since it's a puzzle right now,
I want to get better access to the light fixture from the attic above, and
try to see if I can find a solution to the puzzle.

"Terry" wrote in message
.. .
Anyone care to help BETA-33 get his hallway light working.

Here is what he says he has with no power on anything.

(Knob & Tube)
Light with 2 wires
S1 3-way with 3 wires
S2 3-way with 3 wires

I know nothing about knob and tube. �I am assuming that at one time it
worked with what he has. �(knowing this may not be true)

So..........
The light would have to contain the neutral (coming from anywhere) and
a wire coming from S2

S2 will have the wire going to the light and 2 wires coming from S1

S1 will have 2 wires going to S2 and a dead wire that should be coming
from a source (coming from anywhere)

Does this sound right?

I would think he could look in the attic and be able to see the wire
going from the light to S2

So he should also be able to see the two wires going from S1 to S2.

That leaves the third wire coming from S1. �That wire should be the
one going to a power source.

http://i29.tinypic.com/draz9h.jpg

This sketch is a common arrangement. �Maybe you will have something
similar and can tell where the red wire is going.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

K&T is best replaced few DIYers have the tools and expertise to do it
exactly right, and few electricians will do anything to it for
liability reasons, plus many insurance companies dont want to insure
homes with it.

a electrical system is really a appliance, thats now probably a 100
years old.

how many appliances last a 100 years?

wrote:
(From Beta-33,34,35 -- from a different computer using Google Groups -
yuck)

This probably doesn't help, but when I did the continuity check a long
time
ago, this is what I found:

I tested for continuity with all wires disconnected at both 3-way
switches
and with the hallway lightbulb not in the socket.

At the 3-way switch at the bottom of the steps, I numbered the 3 wires
as 1,
2, and 3.

At the 3-way switch at the top of the stairs, I found wires with
continuity
with two of the downstairs wires, and numbered them as 1 and 2 (the
wires
they connect with downstairs). I numbered the third wire on the
upstairs
3-way as number 4.

At the hallway light, I numbered the wires as 3 and 4. Number 3 has
continuity with number 3 on the downstairs 3-way switch, and number 4
has
continuity with number 4 on the upstairs 3-way switch.


If measured right, some 3-ways were connected as your measurements
indicate. Either 1 or 2 is the neutral, the other is the hot (the blue
wires on Terry's diagram). The odd color on the switch goes to 3 and 4.
In operation each side of the light is switched between hot and neutral.
When both sides of the light were neutral, or both hot, the light is
off. It is not code compliant to wire a new light this way now, but
3-ways sometimes were wired this way long ago. [Anyone know if it was
ever code compliant?]

Probably harder to troubleshoot because the open connection may be
further away - it affects the hot feed to both 3-ways.

-------------
You may have noticed halerb has a fethish about K&T.

--
bud--

"bud--" wrote in message
.. .
wrote:

If measured right, some 3-ways were connected as your measurements
indicate. Either 1 or 2 is the neutral, the other is the hot (the blue
wires on Terry's diagram). The odd color on the switch goes to 3 and 4. In
operation each side of the light is switched between hot and neutral. When
both sides of the light were neutral, or both hot, the light is off. It is
not code compliant to wire a new light this way now, but 3-ways sometimes
were wired this way long ago. [Anyone know if it was ever code compliant?]

Probably harder to troubleshoot because the open connection may be further
away - it affects the hot feed to both 3-ways.


Thanks. I'm going to a little more tomorrow to see what I can figure out.
At this point, it's just a game -- a puzzle that I want to see if I can
figure out.

In the end, I do plan on rewiring the entire house -- either with me doing
some (cutting holes and pulling wires) and an electrician doing all of the
rest, or with an electrician doing the whole thing.

But, for now, I'm having a good time trying to see if I can find where the
disconnect is in the hallway light setup.

On Mon, 04 Feb 2008 09:55:08 -0600, bud--
wrote:

wrote:
(From Beta-33,34,35 -- from a different computer using Google Groups -
yuck)

This probably doesn't help, but when I did the continuity check a long
time
ago, this is what I found:

I tested for continuity with all wires disconnected at both 3-way
switches
and with the hallway lightbulb not in the socket.

At the 3-way switch at the bottom of the steps, I numbered the 3 wires
as 1,
2, and 3.

At the 3-way switch at the top of the stairs, I found wires with
continuity
with two of the downstairs wires, and numbered them as 1 and 2 (the
wires
they connect with downstairs). I numbered the third wire on the
upstairs
3-way as number 4.

At the hallway light, I numbered the wires as 3 and 4. Number 3 has
continuity with number 3 on the downstairs 3-way switch, and number 4
has
continuity with number 4 on the upstairs 3-way switch.


If measured right, some 3-ways were connected as your measurements
indicate. Either 1 or 2 is the neutral, the other is the hot (the blue
wires on Terry's diagram). The odd color on the switch goes to 3 and 4.
In operation each side of the light is switched between hot and neutral.
When both sides of the light were neutral, or both hot, the light is
off. It is not code compliant to wire a new light this way now, but
3-ways sometimes were wired this way long ago. [Anyone know if it was
ever code compliant?]

Probably harder to troubleshoot because the open connection may be
further away - it affects the hot feed to both 3-ways.

-------------
You may have noticed halerb has a fethish about K&T.

So what you are saying is he could have this: (The "Lazy Susan"
switching arrangement)

http://i29.tinypic.com/2ebs4ck.jpg

So he should be looking for a splice in the two wires that go between
each switch.

I don't know how close you have been following the thread, but he used
an inductance pocket tester and has verified that no wire is hot at
either switch or at the light.

I am starting to get a K&T fetish.