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# Garage wiring puzzle

#1
01-10-20, 04:21 PM
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Join Date: Sep 2012
Location: USA
Posts: 27
Garage wiring puzzle

I'm trying to figure out the wiring in my finished garage. It has two ceiling junction boxes, with attached porcelain lights, and three wall outlets.

I'll say up front that all of this was done safely...

I open up what I think is the "main" ceiling junction box and find four armored cables junctioned here. Okay, I think I guessed right. Three of the cables have just a white wire and a black wire, and one of the cables has a white, a black, and a red traveler.

I separated the four ganged black wires and figured out which is the "power in" with a non-contact voltage tester. We'll call this Hot #1.

I connect each of the other Hots, in turn, to Hot #1 and got these results:

* Hot #1 to Hot #2 powers the other ceiling light fixture. This Cable #2 is the one with the red.
* Hot #1 to Hot #3 powers Outlet A and Outlet B.
* Hot #1 to Hot #4 powers Outlet C, and surprisingly, also Outlet A.

Huh?! That last one doesn't make sense to me. Can anyone clue me in to what's going on?

#2
01-10-20, 05:26 PM
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Location: welland ontario
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How are you testing for power?
Did you test both halves of the receptacles?

#3
01-10-20, 05:47 PM
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Join Date: Sep 2012
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I tested for power at the outlets with a three-prong "outlet tester". Yes, both halves of the receptacles were tested. I also pulled the covers and verified that the halves aren't separated; white wire to one side of both and black wire to other side of both.

#4
01-10-20, 06:08 PM
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Location: Northern NJ - USA
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If hot 1 to 4 = C (and A)
Then hot 1 to 3 = A + B + C.

When we check circuits we used loaded voltage testers. Non contact testers are only good for determining there is dangerous voltage in the area as they can very easily read voltages from nearby wiring. An analog meter is good fro testing too. Basic meter runs \$15 at the home improvement stores.

Question: What are you trying to do ?

#5
01-10-20, 06:17 PM
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My tests were repeated multiple times. I'll repeat:

* Hot #1 to Hot #3 powers Outlet A and Outlet B.
* Hot #1 to Hot #4 powers Outlet C, and surprisingly, also Outlet A. And not Outlet B!

Tests on the outlets, as stated, were not done with a non-contact tester but where done with a plug-in tester.

#6
01-10-20, 06:32 PM
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You can't have receptacles randomly picking which cable they work on.
By using a receptacle tester there could be an improper neutral or ground issue.

#7
01-10-20, 06:35 PM
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Dude, I know the receptacles aren't choosing. I'm simply stating the bizarre testing results and looking for help to figure out why. The receptacle tester shows that all outlets are wired correctly.

#8
01-10-20, 07:32 PM
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Location: welland ontario
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The situation you describe is physically impossible.
There is no possible way you can A+B and not C but also have A+C and not B.
There could be a situation with the neutral but then your tester should still show hot all the receptacles.

#9
01-10-20, 08:43 PM
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Yes, that's why I'm posting this. Doesn't make sense.

#10
01-10-20, 10:51 PM
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My next step would be to open the receptacles and see how many cables are coming into each box.

#11
01-11-20, 06:14 AM
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Each receptacle has only one cable coming in, with a black and a white wire.

#12
01-11-20, 06:51 AM
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I think you will have to provide more info as the info you have given seems incomplete.

First what wires are in the second ceiling box?
Second how/to what is the red traveler connected and where does that red traveler go?
What wall switches are in the garage and what is connected to them?

#13
01-11-20, 07:17 AM
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Location: welland ontario
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The red is not a traveller. There is no three way switch. It is another hot. My guess would be part of the switching for the two lights.

#14
01-20-20, 09:46 AM
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Right, I should not have called it a traveler. It is used for switching the lights. Turns out there was another ceiling junction box that was hidden behind a furnace duct. This checks out as the main box for the wiring in the garage.