(Almost) Free Extension Cords - [Using Old Mini Light Strings as Extension Cords]

One of the things you quickly realize when you have an animated display is that you need extension cords - and not just a few!  Wouldn't it be great if you could find a source of free cords?  Chances are, you've been throwing them away and not realizing it.  I'm talking about old mini-light sets.

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In this article:


General Information

Please note that the process here is only applicable for mini light sets.   LED sets are wired differently, or may have rectifiers to make the set DC instead of AC.  My example uses a 100 count light set, but you should be able to adapt the instructions to any count set (70,50,35, etc).


Safety Tips:

Remember, these cords are only going to be good for SMALL amp draws ONLY, typically no more than an amp or 2.  When in doubt, remember the '3 string' rule still applies:  Don't plug in more than 3 strings of normal mini-lights to these cords.

You may also be tempted to remove the fuses from the plug and replace them with a nail or whatever.  DON'T DO THAT! Remember these are very small wires, typically 22 or 24 AWG, which can be overloaded easily.  Those fuses are there to protect the wire and should not be defeated.  


Cut out unneeded bulbs:

Naturally you could darken a normal string by just pulling 1 or 2 bulbs and using them.  But why store all the bulk of bulbs that will never be used again?  Instead, cut out most of the sockets and save room, weight, and confusion.

Unfortunately, you can't just cut out every socket and expect things to work.  Mini lights are simply not wired like that.  If you look closely at a string of lights, you'll notice there are 3 wires that actually run between all the sockets, with the exception of the start, exact middle (bulbs 50 and 51) and end where there are 2.  What you actualy have is 2 parallel circuits where the bulbs in each are wired in series.  If you want to learn more about how mini light sets are wired, check out the Mini-Light Wiring section of my article on Using Your Light Keeper Pro.

Ok, that sounds complicated but don't panic!  Let me simplify it for you: in a regular set of lights, 4 bulbs will have 3 wires comming out of the bottom:  #1, #50, #51, #100 (first, last, 2 in the middle).  We will leave those sockets IN PLACE.  All the others have 2 wires - we'll be cutting those out.

Here is how you do it (click any picture for a close up) 

Start with the first bulb.  See that it has 3 wires?   Image
Image Now go to the NEXT bulb.
See how it only has 2 wires?  Follow that wire back towards the first bulb... Image
Image ... and cut it.  Your first bulb now has 2 wires and will remain like that.
Go back to that 2nd bulb and keep untwisting the bulbs from the remaining 2 wires. Image
Image Don't be affraid of making cuts along the way to make things easier.  So long as you are cutting between 2 bulbs you are OK.
Keep going until you hit bulb 50.  How do you know it's bulb 50?  It has 3 wires going into the socket.  
Cut the wire you have been untwisting at the bottom of socket 50 so there are only 2 wires left.
Image
Image Now go to the next bulb, #51.  See how it has 3 wires?  Skip it and go to #52.
#52 has 2 wires.  Just like you did with bulb #2, follow the wire back to #51 and cut it there.  #51 now has 2 wires.    Image
Image  Just like before, keep unraveling the bulbs, cutting along the way if it makes it easier until....
 ...You get to bulb 100.  Same thing as #50, cut the unraveled bulbs at the botom of #100 so that it only has 2 wires. Image

 You are ALMOST done!



Fill the remaining sockets:

At this point you have a cord with 4 sockets.  You may be tempted to just leave the 4 bulbs in and call it a day.  Don't do that!  If you leave the bulbs in, that cut wire will be LIVE and a SHOCK hazard.  There are several ways to deal with those sockets which will make the cord safe:  

  • Pull the bulbs out and fill the sockets with hot glue or caulk.  This is the easiest and fastest soltion (and the one I use).
  • Use a pair of needle nose pliers and pull each cut wire out of the 4 sockets.  You can then leave the bulbs in.
  • Cut out each socket and use insulated butt-end connectors.

Your cord is now ready for use!



Hints and Tips:

 

  • It takes about 15 mins to make one cord, but it's what I call 'monkey work'.  Monkey Work is something you can do while doing something else - like watch TV.  At the end of this season, put all the sets you would normally throw away into a bin and keep the bin handy.  During the summer next year do a couple of strings every night.

  • Since you can do about 4-5 per hour, you are actually making a pretty good wage.  I realize this isn't quite an apples to apples comparison, but look at it this way:  Figure these are going to be 24' long.  If you were to make or buy a 25' cord, that would be around $4-$5.  That's $16-$20/hr for watching TV.

  • Take all those scrap pieces and recycle them.  There are some recycling centers that will buy your old lights, meaning nothing will be wasted - and you'll make even more money.

  • You won't believe how handy these cords are.  Last year I only had about 10 of them and kept thinking, "What the heck will I ever do with these?"  By the time I was half way through putting stuff up I was wishing I had more!