it just gets weirder

[petedownload]

I need some help with this problem.
I have a customer who tore down a wall in their house. They left a switch box with knob and tube and mc hanging in air.
They asked me to move it, ok, I relocated it to new location in wall 2 feet from original spot using all same wires with one exception.
I ran a new feed line to the ceiling fan, that is what was on this switch previously.

Hooked everything up...122v at fixture, switch on. 0 v at fixture switch off. good.
here we go.
after hanging fan,the lights on fan are dim changing speed on fan brightens bulbs, or turns it off
a light in another location (on the same circuit) is on all the time, but dimly.

I removed fan thinking thats the issue, I got continuity between the hot and neutral lead on the fan on one speed setting.
I think GREAT, I found the issue....wrong.

Now... single bulbs in both locations, both on single pole switches

With both switches in OFF:
ceiling fan location 0v
Mudroom light bounces between 75v and 105v digital and analog meter

With ceiling fan switch on :
122v
with mudroom switch on the mudroom light has 122 v but ceiling fan location drops to 0v
Oh and removing the bulb in the mudroom location removes all voltage in ceiling fan regardless of switch position.

Outlet on this line says open ground.
Anything?

 

[ptonsparky]

Thinking switched neutral on the original K&T. It was a common practice. You may have to pull more wires to make it work correctly.

 

[growler]

They left a switch box with knob and tube.


Outlet on this line says open ground.
Anything?

If the house is wired with knob & tube there wouldn't be a ground ( unless it was added later ).

Figure out which side of the knob and tube is hot and which side is neutral and mark them. Then with the power off make sure your circuit is wired correctly.

 

[mgookin]

You're doing better than my neighbor. He bought a 3 story 100+ year old commercial building a month ago. He had his handy man go in there and tear out some walls on the 3rd floor which he didn't need. The roof collapsed down onto the 3rd floor and the exterior walls leaned out about 5 degrees.

The building fell into the street last week during a storm.

 

[Riograndeelectric]

Sounds like it could be a california 3 way switch wirng. or maybe an lost/ open neutral. or maybe a carter 3 way? with a switched neutral to check to verify what is for sure a neutral and what is a true hot conductor plug in an extension cord form a know source thet you know is wire correctlly run the cord to the switch in question.

Check from the cord neutral a to the switch and see wher you find 120 volt.

then check form hot of cord to switch to see wher you have 120 volt to what you think is the neutral of the switch

 

[jaylectricity]

Definitely a must-have for knob-n-tube installation troubleshooting:

 

[kwired]

Definitely a must-have for knob-n-tube installation troubleshooting:

View attachment 8952

if the neutral is what is switched, those can be somewhat misleading if you don't understand what is happening there.

 

[jaylectricity]

if the neutral is what is switched, those can be somewhat misleading if you don't understand what is happening there.

keywords: If you don't understand

Once you use the non-contact voltage tester, you'll see immediately whether it's the neutrals that are switched. Then you're halfway to solving your problem.

 

[PetrosA]

keywords: If you don't understand

Once you use the non-contact voltage tester, you'll see immediately whether it's the neutrals that are switched. Then you're halfway to solving your problem.

I think the danger is whether he understands that the pencil tester will beep for a loaded, unconnected neutral as well. Can be confusing when dealing with all black wires and a california three way.

 

[jaylectricity]

I still think it's pretty easy to figure out...but on the off chance that you can't: Plug an extension cord into a known 3-wire outlet and test the questionable wires against the hot, neutral, ground of the cord.

 

[cowboyjwc]

You're doing better than my neighbor. He bought a 3 story 100+ year old commercial building a month ago. He had his handy man go in there and tear out some walls on the 3rd floor which he didn't need. The roof collapsed down onto the 3rd floor and the exterior walls leaned out about 5 degrees.

The building fell into the street last week during a storm.

Some walls that he didn't need, but obviously the building did. Oh and I also agree that it's a neutral problem.