Electrical Wiring in the Home/Rewiring lamp


Lamp wire
Lamp wire  
QUESTION: Hello Greg:

We have a pair of table lamps with in-wire switches. Recently, when I switched one on sparks flew out from under the switch. I disconnected the lamp, unscrewed the switch, and noticed the wire was blackened where one of the switch's brass spikes had been (circled in photo).

I bought new lamp wire and a larger switch - 3 amp rocker-style switch - but then I began wondering if I need to rewire the lamp at all.

1. Can the old wire be reused?
2. If so, what do I need to do?
3. Can I reuse the old switch, as well? It's less obtrusive than the big boxy rocker switch and, of course, it matches the other lamp.
4. If I have to cut the lamp wire, can I use scissors or a box cutter/utility knife or combination thereof since I don't have (nor particularly want to buy) wire cutters?

Unfortunately for me, the question of reusing the original wire did not occur to me until after I had removed the wire from the lamp. (But I didn't open the new wire or switch, so I can return those if I don't need them.) I had to break the clear caps covering the two sets of three wires (photo, left side) and remove metal clamps that pinched them together.

5. When I rewire, whether with the old or new wire, is it okay just to wrap the ends together with electrical tape?

Also, just in case the pix are not clear and this is in any way relevant, the lamp has two sockets connected to the one lamp wire. They turn on and off together.

Note that while I have installed ceiling light fixtures before thanks to how-to videos - and they still work perfectly! - I know next to nothing about electrical matters. So please reply in a simplistic "Electrical Repair for Dummies" way. : )

Btw, I did Google everything I could think of but could find no answer to my specific problem, so that's why I'm asking you. Thank you in advance."

ANSWER: From what I can see the wire looks okay. But it is hard to tell from a photo so you are going to have to judge that or take the wire to your local hardware store and have them examine it.

If it is possible I would suggest putting a switch on the lamp. A pull chain or simple push button would work and probably look nicer than than rocker switch that is in the cord.

You would need to drill an appropriately sized hole and it looks like there is enough room for a switch.

---------- FOLLOW-UP ----------

QUESTION: Thanks for your prompt response. As I mentioned, the hole where the thumb switch pierces the cord is blackened where it sparked. So you're saying it's possible that a wire that sparked can still be ok?

I prefer to keep it simple; no way I'm drilling into the lamp. Can the reuse the original switch?

I had asked about cutting the wire (new or old one) with a box cutter because I don't have wire cutters. Is that ok?

I also asked about wrapping the wires with electrical tape. As I said, before I removed the wire they were all pinched together with a metal clamp and covered with plastic caps.

Thank you.

If you cut away the burnt wire so you have clean wire, yes. If the whole wire is discolored then you need to discard it all and ask yourself why did the wire get so hot. If it is just darkened close to the switch then it is pretty safe to say the switch was causing arcing that made the wire hot.
If your whole wire is darkened then you either have too small of wire, or you had a bad connection, or a semi-short.

Once copper wire has become darkened it needs to be removed where it has become darkened.

Again, I cannot tell from the photos so you have to be the judge on if there is enough good wire left.

The original switch is most likely the reason for the burnt wire at the switch, so no you should not reuse the switch.

Scissors are probably better than a box cutter to cut the wire. But to strip the wires you will need some sort of knife if you don't have strippers. But be very careful to not cut any of the strands or you will cause a voltage drop and most likely end up with the same problem.

You can only use electrical tape if you first solder the connections and the connections will be contained in the switch body or lamp. You cannot have any connections exposed.

You can use wire nuts, if there is room to make your connections.
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Electrical Wiring in the Home

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Greg Hughes


Troubleshooting electrical including appliances and HVAC.


34 years of experience.

Both college and tech schools in this field.

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