Wiring a Light Fixture

One of the many things I've had to do in working on our old house is update the wiring on antique fixtures or completely replace wiring in others.  The example I have today I actually pulled out of the garbage when my sister and I were pulling cabinets from a "free" alley pile.  The cabinets are beautiful, and the lamp was cute!

But it was clearly thrown out because of the shredded wiring at the joints.  Since this lamp has an adjustable head, there is more stress on the wires in those spots.  But with just a few supplies, it's not too hard to rewire!

Supplies

For this rewire, I didn't need much to replace existing pieces.  Usually, I reuse every possible item including the light sockets.  Unfortunately, this one just wasn't coming apart the way I needed to reuse most of the parts. Functionally, it's a brand new lamp. 

Parts List:
Lamp nipples
Porcelain Socket with Ring
Swag Lamp Kit

I like this pack of lamp nipples because I don't have to think about the length: I know I'll end up using all of them eventually, and it eliminates the struggle for the right thing.  It is important to get the right size threads.  Since I am replacing the socket, I needed to match the threads to the lamp and purchase the socket with the same size.  This one is 1/8" IP.  This is the most common size for modern lighting, but I have found a few 1/4" IP sizes rewiring other fixtures.  

The other choices were really selecting like-for-like in the best materials I could find.  I wound up replacing a plastic socket with a porcelain one.  Functionally, there isn't much difference, but I verified this one also would fit on my 1/8" IP lamp nipple.  I couldn't find a standard lamp wire that already had an integral switch, so I used wire and installed the switch from a swag lamp kit.  If the lamp socket includes a switch, lamp cord with a plug is available.  For hardwired fixtures, bare lamp wire will work!

Tool List
Needle-nose pliers
Screwdriver (with new materials, usually a Phillips screwdriver; with antique and vintage lamps, a standard)
Wire cutter or quality scissors

Getting Started

Since my lamp has a single socket and is attached to a plug instead of directly wired, I started with pushing and pulling the wire through each section of the lamp.  Unlike when I'll typically use it, I straightened out each piece to reduce the tension during the initial push/pull through each join.  Then I adjusted how much was in the joints to help prevent the breakage that sent this lamp to the trash.  

Once I had enough lamp wire pulled through the lamp base, I separated the two ends of the wire from each other.  Keeping the ends fused helps to get them strung through the base of the lamp, especially lamps with multiple turns and sections.  

Wiring the Socket

To get the socket wired is much like installing an outlet: The silver screw is the neutral side and the brass screw is the hot side.  Getting these two correct means that the little tab on the bottom is electrified when the bulb is removed and the screw threads are not.  On the wire side, there are a couple ways lamp wire is marked for hot and neutral.  On the vast majority of lamp wire, one will be smooth and one will have ridges.  The smooth wire is the hot side, and the wire with -typically- three ridges is the neutral wire.  On rare occasions, the neutral will be marked with a thin, white line.

Before wiring the socket, double check that every single connection point is strung onto the wire as if stringing beads.  If there are any lamp nipples that can be tightened, not is the best time to do that: the part can spin without spinning the wire.  Once the wire is on the screw terminals, these cannot be added later.  

To wire the socket, wrap the wire clockwise around the screw terminal.  The wire should always wrap in the direction the screw moves to close.  The hot wire (black or smooth) will attach to the brass screw.  The neutral wire (white or with ridges) will attach to the silver screw.  On a lamp base, the threaded socket is neutral, and the tab on the bottom is hot.  

Wiring the Switch

This one used a standard turn switch on the cord.  I had a couple options with this: I could use a smart bulb with remote for the lamp, purchase a socket with a key or pull chain switch, or install a turn switch on the cord.  On this one, I used the third option.  

The first thing to do is decide where the switch will be on the cord.  Then, sever the hot wire only.  Keep in mind: the hot wire is the smooth side of the cord.  Separate where the hot is severed from the intact neutral so it can lay on the inside of the switch.  Lay the neutral wire through the switch, and the separated hot wire into the spaces left.  Then, use the other side of the switch to puncture just the hot wire on each end.  I had a hard time getting this to puncture the jacket on the cord, and I very carefully loosened the jacket on the top of the wire, being sure to keep the neutral side intact.  Once the switch mechanism was screwed closed, the lamp was working!

Reassembling the Fixture

Now, the rest of the work is in reassembling the fixture.  At this point, it can be tested first to ensure good connections on every end and to make sure the switch is in working order.  

If there are any pipe nipples that need to be spun, these will cause the wire to twist inside the fixture, creating additional tension on the wire.  I always try to get these spun on during the set-up portion.  Sometimes, it's inevitable that a wire will need to turn inside a lamp.  Go to the next joint or the base of the fixture, and help the wire spin through the fixture to reduce tension on the wiring.  This may need to be tightened slowly in order to move each revolution through the end of the lamp.  

Once each join is attached and the wire has been straightened through the length of the cord, tighten any shades or joints in the lamp, being careful not to tear into the lamp cord.  Once the lamp is fully re-assembled, it is ready for use!