Need help with wiring

I'm finally starting to replace my old X10 hardware.  I decided to start with the vanity.  It's eight bulbs total, four on each side of the mirror.  So, I bought two Aeon Labs DSC27103-ZWUS,White, US,AL001 Aeotec Z-Wave Micro Dimmer because I assumed I'd need one on each side.  Before placing the order, I had opened the fixture up long enough to take a look at the wires.  At a glance, it appeared straightforward.
 
Now that I have them in hand, I'm stuck.  I don't see a neutral.  From my other thread on here, I felt pretty sure that there would be a neutral at the fixture.  But, I don't see it.  I see a three-conductor cable with white, black, plus the ground come in on one side.  On the other side, I see a the same kind of three-conductor come in, and then go back out.  I don't see a neutral.
 
A coupla pictures Vanity1 and Vanity2.  They're big, so I'll just link to them.  In Vanity1, what looks like it might be an extra black wire is just a bit of the sheath.  I took a few other angles, but these seemed to capture pretty much everything.
 
Is there someplace else I should be looking for the neutral?  Did they really not bring a neutral to the fixture?  Am I misunderstanding what I'm looking at?
 
This house is in Richardson, TX (suburb of Dallas) and was built in 1973.  Only one owner, so none of the electrical has been updated.
 
Thanks,
 
Drake

Sorry on my phone right now so can't see the pics, but the lights need a supply wire (hot) and a return wire (neutral) to operate. The only place you may not find a neutral is at the switch since the hot wire is the only one that gets switched. At the load side, you need both the hot and the neutral. I'll take a look at the pics when I get home if someone else hasn't jumped in by then.


Sent from my iPhone using Tapatalk

Was able to download the pictures. The white is the neutral.


Sent from my iPhone using Tapatalk

The white wires are the neutral.  On the box with two cables, one is the feed coming in, and the other carries the power over to the other box and fixture.
 
I'm guessing that you have a wall switch in another box somewhere that controls the lights? There should be a neutral there and you should be able to put just one Aeon micro dimmer there and control both fixtures.

@RAL, yes, I have a switch to control those.  But, I don't have neutral to the switch.  At least, I'm pretty sure.  That's been one of my big issues with trying to update my hardware.
 
@Sparkman1  Thanks.  I've done some more research.  I think I have a switch loop setup, per Wiring Diagrams for Household Switches, mine is (basically) the top one.  At least I thought so.  Now I'm doubting myself.
 
I took a picture of how I have my current X-10 switch wired in there.  I'll be removing that switch.  For now, I'll put the old manual switch back in there and just leave it on all the time.  Eventually, I'll probably just hard-wire that together and stick a wireless Z-Wave/Zigbee switch on top of a plate to close that box.
 

When I installed the X-10 I didn't rearrange any of the wiring bundles.  I simply took the two wires to the old manual switch and attached them to the X-10 switch.
 
I'm trying to picture how those are all wired together.  I see three cables coming into to switch box.  I didn't label this picture, but the third one goes down the right side of the box.  You can see where a white comes out near the bottom, and you can see one of the blacks on the lower-left passes behind the twisted whites.  Does that mean I'm mistaken, and I do have neutral in the switch?  I see some discoloration on the white in the switch box.  Is that supposed to represent/replace the tape?
 
I'm having trouble figuring out why I have three cables in the switch box.  The X-10 manual says Blue is live.  Black goes to the lights.  But, why the two cables after the switch?  I would think that one goes to one Vanity1 and the other to Vanity2.  Except that Vanity1 has both incoming and outgoing cables.  I assume that the outgoing goes off to Vanity2.
 
I might also think that one of the cables in the switch box continues on to the rest of the circuit.  Except, that black cable coming off the X-10 switch to the bundle would mean that the rest of the circuit is switched by the X-10.  And that's not happening.  Where is the split usually done on a circuit to make it parallel?  Is that done at each switch?  Or, is it done in junction box in the attic?  Or, is it done at the breaker box, and the cables run beside each other until they split off down their respective walls?
 
There's a regular dual plug on this wall.  But that's not connected to this switch.  I just tested both receptacles.
 
I feel like I'm missing something obvious.  Hopefully someone can point it out to me?
 
Thanks,
Drake

Looking at the pictures, it looks like the supply line comes into the switch box, and one branch continues to elsewhere, and one branch goes to the vanity lights with the X-10 switching the hot on that branch.  The branch wiring for the vanity lights goes to the first lights and then to the second where it stops.  Looks like a pretty straight-forward install, but this is solely based on my interpretation of the pictures.  If you're not 100% sure how it's wired, turn off the breaker and then disconnect the wiring so that you can measure the continuity of each wire to confirm.  I don't want to sound condescending, and I'm only saying this because electricity can and does kill and you don't seem confident in what you are doing, but bring in a friend that has more experience or if needed, bring in an electrician. 
 
And yes, you do have neutrals at the switch (at least in this case).  
 
Cheers
Al

The blue wire on the X10 switch goes to the light, the black wire is the incoming hot, as per the X10 instructions.
 
I think the cable in the upper right corner of the box is the one that runs to the first light fixture. One of the other two is the incoming feed, and as @Sparkman1 explained, the third cable goes to some other unswitched downstream box or fixture.
 
To determine which cable is the incoming feed, do as Sparkman1 suggested and turn off the breaker, disconnect all the wires and make measurements with a multimeter.
 
From the color of the ground wires, it looks like you have aluminum wiring.  1973 would be the right vintage for that.  If so, make sure the wire nuts you use are rated CU-AL.  Back when aluminum wiring was first installed, switches, outlets, and wire nuts were not rated for aluminum, and that's a fire hazard.
 
[Edit]:
 
Sometimes it helps to have a picture.  Here's what I think you are dealing with.
 

 
It's possible that cable2 is really the feed from the breaker and cable1 is the unswitched out to the next fixture. That's where  the multimeter will help you figure it out.

What had me uncomfortable is that this is different than what I had been told to expect.  I was expecting the source to go to the fixture, and then a loop to go to the switch, with the tape on the white to show that it's hot.  I understand how this arrangement works.  But I was under the impression that it's non-standard.
 
I'll verify with the multi-meter.  But, now that you're telling me that this is another standard arrangement, I can deal with it.
 
I appreciate the help.  Especially the note on the wire nuts.  This house is wired with aluminum.  I know that in most of the switches I used the nuts that came with my X-10 switches.  I'll buy some aluminum-rated nuts, so that I'm sure that they're good, and I'll go back and replace the others.  Actually, I might go back to the original switches until I'm ready to replace them with smart hardware.
 
Drake

Actually, it's not just using the proper AL-CU fittings....that's not enough, you need to cover the joints with no-ox as well.

Repairing aluminum wiring to make it safe is a real pain.
 
Although I said earlier to use a CU-AL rated wire nut, it turns out they are not considered safe by the Consumer Products Safety Commission, even though they are UL Listed and comply with the NEC for copper to aluminum connections.
 
Early switches and receptacles for aluminum wiring were originally rated CU-AL, but have been superseded by an improved design called COALR (or CO/ALR)). But they, too, are not considered completely safe to use with aluminum wire by the CPSC. 
 
The only method the CPSC considers to be safe for connecting devices to aluminum wiring is to use a copper pigtail to the device, and then join it to the aluminum wire with an Amp/Tyco COPALUM crimp connection or an Alumiconn connector. 
 
Amp/Tyco only leases the special crimp tool required for crimping the COPALUM connector to trained electricians, so the Alumiconn connector is the only practical solution for the DIYer.  But even the Alumiconn connector requires careful installation practices.
 
For the OP, I would check the wiring to all the switches, outlets and fixtures in your house to see if they have been connected with copper pigtails and proper splice connectors.  If not, you may have a serious fire hazard.  Things may not be causing a problem today, but you don't know when a failure might occur.
 
More reading on the subject: 
 
http://www.cpsc.gov//PageFiles/118856/516.pdf
 
http://inspectapedia.com/aluminum/Aluminum_Wiring_Repair_COALR.php
 
http://inspectapedia.com/aluminum/Aluminum_Wiring_Repair_Methods.php

Okay.  I have verified with the multi-meter that that center cable, attached to the blue lead, does, indeed go to the fixture.
 
I also spotted, farther down on Wiring Diagrams for Household Switches, "Controlling Two or More Light Fixtures," which looks like my situation.  I pasted in the top wiring diagram from the Aeotec page.  Assuming I leave the switch on all the time, (or, follow the dotted line and just don't use the switch) I think this is how I want to wire in the dimmer.
 
The source black and white go into the center two spots on the device.  The black and white headed out to the fixture go into the outer connections.
 
Does that look correct to you?
 
Drake

RAL said:

Repairing aluminum wiring to make it safe is a real pain.

Click to expand...

Nothing substantial has been done to the wiring in this house since it was built.  So, the standard in '73 is how it all stands, right now.  I haven't seen any copper pigtails on anything I've opened up in the past.
 
Drake

Mighty said:

Okay.  I have verified with the multi-meter that that center cable, attached to the blue lead, does, indeed go to the fixture.
 
I also spotted, farther down on Wiring Diagrams for Household Switches, "Controlling Two or More Light Fixtures," which looks like my situation.  I pasted in the top wiring diagram from the Aeotec page.  Assuming I leave the switch on all the time, (or, follow the dotted line and just don't use the switch) I think this is how I want to wire in the dimmer.
 
The source black and white go into the center two spots on the device.  The black and white headed out to the fixture go into the outer connections.
 
Does that look correct to you?
 
Drake

Click to expand...

 
Yes, that looks like you've got it right.

Thanks for the double check.
 
I'm currently reading up on the aluminum wiring thing.  I had heard about concerns with aluminum wiring several years ago.  But, the impression I came away with at the time was that it was generally safe, unless it used undersized wiring, was greatly overloaded, or, was just poorly installed in the first place.  Sounds like the common wisdom has changed since then.

Mighty said:

Thanks for the double check.
 
I'm currently reading up on the aluminum wiring thing.  I had heard about concerns with aluminum wiring several years ago.  But, the impression I came away with at the time was that it was generally safe, unless it used undersized wiring, was greatly overloaded, or, was just poorly installed in the first place.  Sounds like the common wisdom has changed since then.

Click to expand...

 
The problem with aluminum wiring isn't so much with being undersized or overloaded.  Even at low currents, it can fail and cause a fire.
 
One problem with aluminum is that it expands and contracts differently than copper.  This can cause connections to come loose over time.  Another problem is oxidation.  With copper, when the wire oxidizes, the copper oxide is conductive and doesn't affect the quality of the connection.  Not so with aluminum.  Aluminum oxide increases resistance in the connection, which causes it to heat up, and that can cause a fire.  That's why you're supposed to treat the bare wires with an anti-oxidant paste.
 
You'll still find lots of debate over whether aluminum wiring needs any repair work.  Some argue that if it was properly installed, with switches, receptacles, connectors that are rated for use with aluminum, plus anti-oxidant paste or gel, nothing needs to be done.  The key is "properly installed."
 
It's very hard for a typical homeowner to tell if this is the case.  You can do some checking on your own by looking for CU-AL or COALR markings on the switches and receptacles, and signs of anti-oxidant paste/gel.   If you see any connections that are made using the rear push-in connectors, rather than screw terminals, that's a bad sign.
 
If you have any doubts, the best thing to do is have a licensed electrician check it out, and ask them to explain why they think it is or isn't safe.