Lighting circuit just quit.

[Bunchgrass]

I have a lighting circuit running 2 fixtures using 2 3-way switches. All of a sudden neither of lights works. The sequence is POWER to 3-way to 3-way to FIXTURE to FIXTURE.

Checked power = good. Power to 2nd 3-way = good Power to first fixture = good.

Tested with basic noncontact tester.

Removed one fixture and replaced it with a basic ceramic keyless lamp holder = no light.

So my next thought is open neutral somewhere (at either switch). God forbid it's a mouse related problem.

Thoughts?

 

[Shiftless]

You mentioned mice...
If you’ve checked the bulbs I can’t see any other explanation.
anybody else have an idea?

 

[The Cobbler]

is there power coming into the circuit?
a bad switch?
a bad connection?

 

[bigmike989]

Make sure both switches are to their extreme position. I've had a 3-way stop in the "middle" with no connection. It just needed to be bumped.

 

[Shiftless]

Here’s your wiring, right? (Second fixture added in parallel to the one here on the right)

You said this “ Checked power = good. Power to 2nd 3-way = good Power to first fixture = good.”

That implies that there is power to first fixture so that one works OK??

If so, you’ve got an open somewhere between the 2 lights.

 

[PCustoms]

Get a real tester.

Those non contact tester are prone to false voltage readings

 

[TRWham]

You said it: Check the neutrals. Power is useless if it has no place to go.

 

[Pingel85]

Agreed, I would look for an open neutral

 

[Terry D]

Get a meter that reads voltage, that non contact tester will not tell you if you lost a neutral and alot of times when it tests hot, it might not be 120 volts. Remember, all white wires in a 3-way switch circuit are not neutrals

 

[nadogail]

IMHO, Non contact testers have limited value in trouble shooting; but they can help you stay alive.

You now need a "Real" multimeter.

 

[Bunchgrass]

So if I have an open btwn the 1st and 2nd fixture why wouldn't the first one work? The neutral (common) should complete the circuit from that fixture back to the panel, no?

Note -- there was nothing done to this circuit before the failure. It just stopped working one AM.


More info --- there are other outlets between the panel and the first 3-way switch. They are both fine. Also another switch in the first box with the 3-way and tying into the same common as the 3-way. IMO --- this indicates a problem somewhere between the 1st 3-way and the fixtures

 

[yatg]

Check all connections, including the neutrals wire-nutted.

Backstabs to the switches are bad.

Check for 120v between hot/neutral at your first switch, second switch, first light. That will tell you more.

 

[Shiftless]

So if I have an open btwn the 1st and 2nd fixture why wouldn’t the first one work? The neutral (common) should complete the circuit from that fixture back to the panel, no?

Note -- there was nothing done to this circuit before the failure. It just stopped working one AM.


More info --- there are other outlets between the panel and the first 3-way switch. They are both fine. Also another switch in the first box with the 3-way and tying into the same common as the 3-way. IMO --- this indicates a problem somewhere between the 1st 3-way and the fixtures

I thought you said in your first post that you had power to the first light fixture?

“Power to first fixture = good”

 

[Bunchgrass]

Maybe I was unclear, sorry.

I do have POWER to the first fixture. Checked the hot. Installed a cheap ceramic keyhole lamp holder and ..... no light.

More and more this seems to indicate and issue between this fixture and the power coming into the 1 st 3-way.

 

[PCustoms]

Get a real meter.

 

[Bunchgrass]

Checked neutral/common connections -- look good/solid tight.

Using my meter ==

Checked power at fixture box (probe to hot and white common) -- 120V
Installed keyhole lamp holder and tested socket ( probe to threaded portion and tab in base) --- 120V
Put functioning light bulb into lamp holder --- nothing.

I'm totally lost now. How I can have 120V and not get a bulb to light is .... confusing?

 

[larry4406]

Turn breaker off.

Reach into keyless socket and pull the brass tab at the bottom of the socket up so it makes contact with the bulb. Insert known good bulb.

Turn breaker on. Let there be light.

I have had several light bulbs that didn't seem to thread enough into the socket to engage the brass tab at the bottom.

 

[Yankeefarmer]

Checked neutral/common connections -- look good/solid tight.

Using my meter ==

Checked power at fixture box (probe to hot and white common) -- 120V
Installed keyhole lamp holder and tested socket ( probe to threaded portion and tab in base) --- 120V
Put functioning light bulb into lamp holder --- nothing.

I'm totally lost now. How I can have 120V and not get a bulb to light is .... confusing?

Very carefully, with the lampholder hanging out of the wall or ceiling, and a known good bulb in it, use a meter to measure voltage across the lampholder. If you have a bad connection or almost severed wire, it’ll cause high resistance such that you can measure 120 v with no load, and 0 volt with a load.

 

[Bunchgrass]

More troubleshooting.

1) Removed 3 way switch nearest the fixture. Attached hot and common from a separate circuit to the switch leg. Works. So apparently not a switch leg/fixture issue.

2) Tried a single pole (all I had in the toolbox) using one hot lead from 3-way circuit and switch leg black --- commons tied. Nothing.

3) Checked voltage at both red and black of this 3 way -- 113V when touching the isolated common. When the common was connected to the switch leg that number rose to 122V. What IS that?

One step further --- connected hot to black switchleg directly (wirenut). Nothing. Same with red. IMO this all seems to point to a problem with the common but I can see nowhere for there to be an issue (either of the boxes). Any ideas at all?

 

[Bunchgrass]

Latest --- I took some 12g wire and jumped from the common at the first 3way box to the light switch leg bypassing the common between the switches and we had light. So clearly the issue is the common in that run. Next question. How to remedy. I will check the run under the house but it's very possible this is in the wall between the switch box (either one) and the floor. Pull a whole new piece of 12-3?

 

[cybrdyke]

this is why I chuckle when I hear folks put down wireless switches. All the extra aggravation of pulling wires, figuring out which wires go where, and then at the end, they still dont work right. And then fixing them is even more of a headache.
Yeah, wireless switches are more expensive. But install them in 10 minutes and they work.
They're not voodoo. They've been around for 10 years with millions of satisfied customers.
www.casetawireless.com

Good luck,
CD

 

[Bunchgrass]

Bas turd mice! This is 4 yr old construction. Under house.

 

[Bunchgrass]

But wait. There's more. At the switch box and in the cavity leading to the switch box.

 

[Bert_]

Ouch, looks like you've got a bit of a mouse problem. I don't know why they like wires so much.

 

[Bert_]

this is why I chuckle when I hear folks put down wireless switches. All the extra aggravation of pulling wires, figuring out which wires go where, and then at the end, they still dont work right. And then fixing them is even more of a headache.
Yeah, wireless switches are more expensive. But install them in 10 minutes and they work.
They're not voodoo. They've been around for 10 years with millions of satisfied customers.
www.casetawireless.com

Good luck,
CD

They've got a place sure, but I don't want them everywhere. You've still got to run wire for a wireless switch, maybe to only one location but it's not immune to these problems.

I've got a few original switches in my house. Got to be 100 years old. When wireless switches have that kind of track record we can talk.

 

[Bunchgrass]

Got wireless outlets too? Kind of need both.

 

[Bunchgrass]

Mice are a serious issue here. We farm and have a constant battle with mice. They get in any rigs not being used for more than 7 days. Sometimes even if they are being used. Get in the cabin air filter/fan etc. You can trap or poison as much as you like --- it's like clone wars. They just keep coming.

 

[Jim greengo]

Get a real tester.

Those non contact tester are prone to false voltage readings

What he said

 

[Bunchgrass]

If you read above, I got off my ****, went to the shop and retrieved my multi-meter.

 

[Shiftless]

I’m afraid that unless you get that mouse problem under control quickly, you’ll have more and more problems.

Not to mention the careless people who nailed on the sheathing.

 

[Bunchgrass]

Yep -- give a monkey a nail gun and see what you get.

Probably going to use a j-box to connect the other good end of this run to new wire going i to replace this mess. Then foam with steel wool in the hole.

 

[The Cobbler]

I've heard suggestions that as we try to get more environmentally friendly with products, soy is being used in wire coatings and it attracts varmint

 

[Shiftless]

Yep -- give a monkey a nail gun and see what you get.

Probably going to use a j-box to connect the other good end of this run to new wire going i to replace this mess. Then foam with steel wool in the hole.

Rats are quite damaging. I have fought them in my house. One of them chewed through half inch Sheetrock. Another attacked a 36 pack of water bottles and apparently got an adequate water supply to continue his carnage.
I used the steel wool/expanding foam to seal entry cracks in our 70 year old house crawl space. Sheet metal glued onto holes with Liquid Nails or PL Premium works very well.
I set a couple of electronic rat zapper traps baited with dry dog food.
It’s a war. You have to go to battle.

 

[cybrdyke]

Bas turd mice! This is 4 yr old construction. Under house.

Another reason for wireless. Fewer wires to chew on.
CD

 

[Jay H 237]

If possible I'd consider replacing some of that with BX, let them chew on that!

 

[MatBirch]

Ouch, looks like you've got a bit of a mouse problem. I don't know why they like wires so much.

Don’t know about new house wire, but with automotive stuff, many newer wire insulation’s are made with soy. Rodents love a free snack!

 

[Milton Shaw]

From what I understand the soy insulation is so good tasting to termites that that is what is used in the bait stations for determining termite infestations. This was first discovered by electricians finding underground wire completely stripped of insulation by the termites. A friend who is an exterminator told me this.

 

[rburke65]

Traps,poison, and conduit.

 

[TractorJeff]

Traps,poison, and conduit.

You forgot to say CAT! Most, not all Farms I go to have a CAT wandering around.

 

[Bunchgrass]

We have a car wandering around. She wanders back and forth to the food bowl and only snags a mouse when they've reached epidemic levels.

CAT not car.