Submitted by Cappuccino_Crunch t3_10nuw2r in DIY
I have a new work box with a keyless lamp fixture. Neither of these have a ground. Both the hot and neutral wire have 120 v running to them. The light won't turn on and the only thing I can think of is the free ground wire. If that doesn't have anything to ground to could that be preventing the light from turning on? It's hooked up to a single pole light switch with the ground wired on that one with the two hot wires.
My multimeter. Klein m300 I think
Where did you put your two probes to measure 120v on each wire?
The black to ground and red to the hot wire then to the neutral wire.
Then your ground is properly connected and your neutral is not neutral or does not make it back to the panel.
Is that something with my wiring or something hidden I can't see? Both my neutral wires on load and line are twisted together and capped. I'm using new Romex 14/2. House was built in the 70s.
Sounds like I have some work to do. Thanks I may post some more tomorrow.
What is your voltage from the switch terminals to neutral in the light switch?
Everything is either 120 or zero. Someone pointed out that there is probably an open neutral upstream which is confirmed by a diagram we made with the circuit when I moved in.
Yeah, that's why I said it doesn't make it back to the panel.
But if that were true, the number you would read with one probe on black and one on white would be zero, or close to zero.
Edit assuming you see 120v from black to copper.
Though with the light switch off I still get a live wire warning with my non contact tool at the light which I thought was weird.
Are you testing it with the light still up, or with it down and the two wires completely separated?
Light is hanging down and connected. I initially tested it before I hung it
Disconnect it, make sure the black and white wires aren’t even twisted, and separate them opposite each other in the box and retest.
Here it is in detail and separated. https://imgur.com/a/kNP90sA
At the switch, do you have one black that is showing voltage and one that is not, and are the neutrals showing correctly?
Then at the light, with the switch off, are both showing 0?
At the light the neutral shows 120 with the switch off which I'm pretty sure isn't supposed to happen. I haven't checked the connected neutral wires at the box since it's capped off.
That absolutely should not be happening. Separate and test both neutrals at the switch box.
Ok separated the neutrals at the box. In the off position the line black wire reads 120, the load (to the light) reads zero and the line neutral reads 120 and the load neutral reads zero. So at this point everything is zero at the lamp.
With the switch in the on position, all black wires read 120. The line (from the source) neutral reads 120 and the load neutral reads zero. So at the lamp with the switch on the neutral is zero and the hot is 120.
This is with the lamp removed and the neutral wires untwisted but the grounds and hot at the switch hooked up.
The issue is the neutral at the switch showing voltage. That shouldn’t be happening. What else is on that circuit?
So I pulled out our map for the electric that we made. https://imgur.com/a/51ir7wO. I'm working on 28. I'm guessing that open neutral is what the plug tester read when we went around testing the outlets. I have a bad feeling lol.
Work your way backwards through that circuit to find where the issue with the neutral is.
Is that what's causing my issue? And work back towards the main from the point where it says open neutral?
Yes. Somewhere upstream, the neutral is crossed and is picking up voltage.
Thanks man you've been super helpful. My question is why doesn't the rest of the outlets show that open neutral on the circuit downstream? Is it because I separated the two circuits at the switch?
That I’m not sure. Something like that is hard to diagnose without being there and seeing it.
Alright cool. I'll open that outlet tomorrow tomorrow and the ones upstream to figure out how to fix the neutral.
Now I'm at a loss. Gonna call in a pro now.
Actually, I think I see the problem. Disclaimer: I’m not an electrician, just a somewhat experienced amateur, but for the life of me, I don’t see why that neutral is bundled and capped with those hot wires. That’s likely where your neutral picking up that voltage is coming from.
I will gladly step aside and admit defeat if a professional wants to contradict this answer.
Ok. So what should I do with that neutral? There's three bundles in there. Two go to a light switch/fan plate that operate on two different breakers.
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Ok, disregard my previous comment. How many b/w pairs are in that box? There should be 4: two on the hot side of each circuit and two that lead downstream.
Disconnect and separate everything. Then organize the wires by pair. Then, test to see which is the hot coming in from each circuit. Then you’ll have to do a little trial and error to see which of the downstream pairs goes to the light vs the switch.
Confirm this and let me know.
I only have three pairs. This seems like a good stopping point for me actually lol. Running a switch to a light seems pretty easy. I appreciate the help though.
Is that a split outlet? In other words, does the switch control one half of it and the other half is on the other circuit? If so, I have your solution.
The circuit that the switch is on was designed to terminate at that spot. With the power and the switch on, find the hot wire for that circuit. Then, connect that pair to either the top or bottom of the outlet.
With the remaining two pairs, you’re going to have to make two pigtails. Take a spare piece of black/white wire accordingly and cut off about 9-10”. Strip the ends and with a wire nut, bundle the two black wires in the box together with one pigtail, and do the same with the white. Connect the other side of the pigtails to the open half of the outlet accordingly.
I'll just call an electrician tomorrow to figure out this neutral issue. Is that what's causing the light fixture to not work? If so I'll do the hook up myself since that part is pretty easy
With the switch on both blacks show voltage. The the switch off, only the one shows 120 as the other shows 0.
This side is correct then.
There should not be 120 on the white and black. The romex wire going thru the switch box is black, white & ground. White to white. Black split by switch. Ground to ground. In your light box, Ground wire to the light fixture ground. Black wire to darker brass screw and white to other lighter brass screw.
That's how it's hooked up. Except I have no ground screw in the light. It's a plastic new work box and a plastic fixture with a hot and neutral screw with no ground.
Okay, The missing ground screw doesn't cause 120 in your common.
Here are pictures and some explanation. https://imgur.com/a/kNP90sA
Just fyi, when splicing Romex with wire nuts, you're supposed to twist it until the insulated part of the wire pair starts to twist as well. That neutral wire doesn't look like it got twisted enough
Ground wire is not the problem. Switch should only control the Hot wire.
1)Do you have 120v at the line side of your switch?
2)Do you have 120v on the load side of the switch when it's on?
3)Do you have continuity of the hot conductor from switch to your fixture?
4)Are you sure your fixture works?
5) are all your connections secure and properly done?
Ok with switch in off position and wires not connected to fixture: The neutral reads 120v and the hot zero. With it in the on position both read 120v. That's the light fixture.
The hot wire from the source always reads 120v regardless. The wire at the switch going to the fixture reads zero when the switch is turned off and 120 when on. The neutral wires are capped and the grounds are spliced with a pigtail to the green screw.
I purchased another fixture and light switch earlier today so I don't think that's the issue. Should the neutral at the fixture be reading 120 with the switch flipped to off?
Why is your neutral reading 120? There should be no voltage on your neutral unless its part of a closed circuit. Are you sure your wires? Older houses did not pull neutrals to switches and often used a white wire in the pair as a switched or hot leg. You may want to post a couple pictures.
I will. I thought that was odd as well
Take the lamp out, and with the switch on, check if the socket has power. If you read 120v at the socket, it's the lamp. Or the metal plate at the bottom of the fixture isn't making contact with the lamp.
Switch on, both hot and neutral reads 120 disconnected and separated at the ceiling. Switch off, the neutral reads 120 but the hot reads zero.
How are you measuring voltage on the neutral? One prong on the neutral, the other on the ground? Or are you using a voltage sensor?
Thank you. So do you have 120 from the source (left side) between the black and ground in the swich box - maybe dm me
Sevulturus t1_j6azjrq wrote
What are you using as your reference to find the 120v?