We have a detached shed (now man cave/shop) that was built by a prior owner 40 years ago. Code was ignored and wiring practices sloppy. I am chasing down circuits, re-doing some of the sub-panel that feeds the shed, etc. I am down to one circuit that is giving me fits. The circuit contains two light banks, an outside dawn/dusk light, two switches and a receptacle next to the switch. The receptacle has three blacks, three white neutrals and grounds which are pigtailed to the normal green on the receptacle. With the switch that controls the outside dawn/dusk ON, I am testing Hot -Ground reverse. With the switch off, I am testing open neutral. Anybody know what this guy did when he wired it? Why three hots/three neutrals? He wired two hots and two neutrals into those stab holes which I despise. This ought to be obvious to me but I am drawing blanks. Thoughts? Help trouble shooting or straightening this out? Thanks
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Obviously, somewhere prior to the switch he reversed hot and neutral.
Not an electrician, but could the reverse have hapened in the wiring of the light fixture?
Need to determine what feeds what.
If it were me I think I would see if I can find an obvious reverse and correct it if not, then make sure I knew how it was wired and then take it apart and determine what feeds what and see if I could rewire to correct the problem
I'll check the light fixture
I'll check the light fixture tomorrow when I have light and can pull it. Good idea. I probably should pull the switch as well and see if I can determine what is feeding what.
There's nothing unusual about
There's nothing unusual about bundling hots together and neutrals together; that's a normal aspect of parallel wiring. But based on what you have described there are probably other issues.
Any chance you could post a few pics?
Why would the switch determine what is testing open? I think I would have wired this without the switch. There was a loose neutral when I opened the box. From the length, it came from a back stab. It had clearly been out for an extended period based on the green patina. It was pushed back in before the picture. Pictures attached. Ask away as to any questions that may help resolve this.
The switch would cause neutral to "test open" for one of two reasons:
1) The switch is wired into the neutral leg rather than the hot. You can't trust the color of the wires.
2) The switch is "back-feeding" an open circuit.
You really need to start from first principles: Disconnect all the wires, determine which wires are the feed into the box (and whether hot/neutral are reversed coming in), then determine, one by one, which wires feeding out go where. Then reconnect everything logically.
Note that the wire you reconnected may have been disconnected for a reason -- it may have been compensating for a wiring screwup somewhere else.
It looks like he used the receptacle as a wire nut as opposed to splicing and running a pigtail to the device as is common practice. If the device connections are good the problem is elsewhere.
Since you mentioned the loose neutral looked like it had been off for a long time I'd trace where it goes and see if the missing neutral was replaced with a jumper to ground to "solve" the problem.
Also check the feeders from the panel end and see if they may be crossed somewhere or have a weak short. Old rusty boxes are not real good conductors. You may have a nicked wire or loose connection that will kinda work and not blow the breaker.
This calls for some wire tags, a note pad, VOM and patience.
I'll bet the neutral is
I'll bet the neutral is switched.
Good thought. I'll check
Good thought. I'll check that first tomorrow. Thanks.
I think CAP is onto the problem.
Having worked behind some "mechanics" myself. I tend to take a "straighten-out-the-whole-system" approach to avoid any future confusion especially when the system is in my own house.
This obviously takes more time.
In your case, I would be inclined to disconect everything from the outlet and determine what is what, and what goes to where. I suspect that the outlet box is the entry point for this circuit into the shed.
I think you will find your "line in" for the entire circuit in this outlet box. Find it, mark it, cap it. Now you are down to 2 mystery cables - 2 black & 2 white conductors. Confirm there is no voltage present in any of the remaining 4 wires.
Open the other boxes and fixtures involved and disconnect there also.
I start looking for continuity in individual conductors at this point. Long ago I made a 100' long test lead from stranded speaker wire - has alligator clips on both ends of the wire and travels wrapped around an old wire spool.
In your case I would clip one alligator clip onto a "mystery wire" at the outlet box, go to other boxes and start looking for continuity at any of the wires there. Label both ends when you find continuity. Repeat until you identify all conductors.
Like someone else mentioned, start drawing a map.
Take nothing for granted - just because a white wire shows continuity between box #1 and box #2, do not assume that the black wire in the same Romex at one box is also continous to box #2. Previous "mechanics" sometime bury j-boxes with messed up connections.....so what started in box #1 as a white wire may appear in box #2 as a black wire - velly interesting.
Once you have identified all of the conductors, you can reconnect everything probably with no problems.
Remember to remove any incandescent light bulbs in the circuit -they will produce continuity between hot & neutral and serve only to confuse you during testing.
Good luck!
Jim
Keith,
Above replies are all good advice.
You need to be systematic in your investigation/fix.
Be aware that multiple faults can fool that tester you are using. Trace everything out, connect properly, then retest.
Regards,
--Jim
Everything on that circuit now works correctly. Thanks to everyone for all of the great help. The hots were wire nutted together in the switch box and the switch was wired with the neutrals. Nothing was grounded properly. All straight now. As to tracing and sketching the circuit, I was not able to make much progress. I never could get a hot or neutral to give me continuity back to the panel. I am fairly sure that there are hidden buried junctions in the walls or more likely, in the shed roof. Again, it is all fixed and I really appreciate the help.
Keith