[How to:] Fix frayed wire on Lego 9v track connector

[Unfinished_Projects]

How to: Fix frayed wire on Lego 9v track connector

 

Materials:

Frayed wire

New wire

Heat shrink crimp connectors

Heat shrink tubing

Wire strippers

Razor blade

Lighter or heat gun

 

Step 1: 

Cut wire between track connector and ferrite core (black cylinder), cutting as close to the ferrite core as possible.

Step 2: 

Cut wire at similar length on the controller end.

Step 3: 

Strip back rubber insulation from controller end, track connector, and new wire.

 

Step 4: 

Crimp wires together, sliding the heat shrink crimps as close to the connector as possible. DO NOT FORGET TO SLIDE HEAT SHRINK TUBING ON, IF YOU ARE USING IT. (I forgot for one half)

Step 5: 

Use lighter or heat gun to melt shrink tubing, again sliding the heat shrink as close to the connector as possible.

 

 

 

Step 6:

Repeat for wire between track connectors if needed

Step 7:

Test

*Disclaimer*  There may be a better way to do this.  I simply used what I had to fix the problem.  No guarantees that this will work for you. 

Thanks for reading and hope this helps someone,

Unfinished_Projects

[Pdaitabird]

Thanks for posting this! I just unpacked my old 9v gear, and it's starting to get frayed, so I'll have to do this eventually.

[JopieK]

Nice fixes! Another solution would be to use 'Sugru' or some other kind of 'putty'.

[LEGO Train 12 Volts]

Very well done!

Thanks for sharing!

[fred67]

I'm actually not enamored by this solution.  First, you have the problem where the second connector is also suffering from dry-rot and losing it's insulation.  This solution makes the wires going into the second connector really stiff, maybe not even flexible enough to connect.

Secondly, the stiffness itself is bothersome to me, although I would prefer it over non-working trains at all, of course.

I also feel like the dry rot may have gotten far enough inside to still cause a short.

I admit I'm only halfway towards making them work (I need more wire), but my biggest problem was getting the 9V connector to open up.  Now here's where flexibility doesn't really matter, so using this solution to fix the wires going to the 9V connector is great (and I wish I'd known before absolutely destroying both of mine trying to open them).  But separating the track connectors was not that bad using a set of jewelers screwdrivers (which you can find on clearance tables at places like Ace Hardware for a couple of bucks for the whole set).

I also saved the noise suppressor, although I don't know that it really matters.  It's just a plastic housing for a magnet loop.  No big deal to put back on.

So my solution is short PF cables (like these) that have the old 9V connector on one side, and splice in new wire (I'm thinking 18 or 20 AWG) using the technique described in the OP, running it through the noise suppressor (why not?) and then having ONE wire go to each of the track connectors.  I may run both through, like the original connector, but I don't know why bother (just remember to flip the polarity in between).

In any event, no matter how you do it, you can at least now choose wires insulated in the color of your choosing - I will definitely make one white set for Christmas trains.

 

[Unfinished_Projects]

2 hours ago, fred67 said:

I'm actually not enamored by this solution.  First, you have the problem where the second connector is also suffering from dry-rot and losing it's insulation.  This solution makes the wires going into the second connector really stiff, maybe not even flexible enough to connect.

Secondly, the stiffness itself is bothersome to me, although I would prefer it over non-working trains at all, of course.

I also feel like the dry rot may have gotten far enough inside to still cause a short.

I admit I'm only halfway towards making them work (I need more wire), but my biggest problem was getting the 9V connector to open up.  Now here's where flexibility doesn't really matter, so using this solution to fix the wires going to the 9V connector is great (and I wish I'd known before absolutely destroying both of mine trying to open them).  But separating the track connectors was not that bad using a set of jewelers screwdrivers (which you can find on clearance tables at places like Ace Hardware for a couple of bucks for the whole set).

I also saved the noise suppressor, although I don't know that it really matters.  It's just a plastic housing for a magnet loop.  No big deal to put back on.

So my solution is short PF cables (like these) that have the old 9V connector on one side, and splice in new wire (I'm thinking 18 or 20 AWG) using the technique described in the OP, running it through the noise suppressor (why not?) and then having ONE wire go to each of the track connectors.  I may run both through, like the original connector, but I don't know why bother (just remember to flip the polarity in between).

In any event, no matter how you do it, you can at least now choose wires insulated in the color of your choosing - I will definitely make one white set for Christmas trains.

 

Thanks for the input, that would definitely be more ideal! Like I said in the disclaimer, I simply used what I had to fix it up. Ideally I'd get out the soldering iron, used correct guage wire, and all that. But, this works for now. Thanks again for the input, I'm sure it will help someone looking to do a cleaner, longer lasting repair.

Unfinished_Projects

[Unfinished_Projects]

UPDATE:

I took the time to do a better repair. I ordered some 22awg stranded ribbon wire and peeled off 2 wires to use for the repair.

This time I opened the track connectors with small flat head screw drivers. Inside I twisted the wire around a hole in the metal, that is used to hold the metal in place, but worked good for holding the new wire. Then I closed the track connectors back up and since some clips had broken, used a lighter to weld them closed. 

For the standard 9v connector I opened it as described in many locations around the internet, and pressed the wire onto the original prongs inside.

This all resulted in a much nicer repair, that I'm quite happy with (the color looks cool too! )

Unfinished_Projects

[XG BC]

if i where you i would additionally solder the wires in place to prevent loosening. (Assuming you have a soldering iron of course) but anyways its a good solution that works without soldering any wires.

XG BC

[Unfinished_Projects]

4 hours ago, XG BC said:

if i where you i would additionally solder the wires in place to prevent loosening

I thought of doing that, but my soldering skills are decent at best so I went without. 

Unfinished_Projects

[Arrow]

22awg is the correct diameter of the original wires?

[Unfinished_Projects]

12 minutes ago, Arrow said:

22awg is the correct diameter of the original wires?

I wish I could say it definitely is, but I've found that it depends. So far I've bought 22awg wire from two different places, and the first one seemed thicker than the wire I used here. I'm guessing it's a problem with the cheap wire I bought the second time around. Unfortunately I would suggest trying a few different sources if possible, or purchasing in person. 

Unfinished_Projects

[Arrow]

Thanks. I only need to know how to open that 2x2 black wire brick without damaging it =(

[XG BC]

21 hours ago, Unfinished_Projects said:

I thought of doing that, but my soldering skills are decent at best so I went without. 

Unfinished_Projects

ok i didnt know that, but you will get better on soldering as you do it more.

XG BC

[Toastie]

On ‎3‎/‎13‎/‎2019 at 3:21 AM, Unfinished_Projects said:

This all resulted in a much nicer repair, that I'm quite happy with

It really is!!!

Very nice.

But you should mention (correct me if I am wrong!) that you need to modify the "base" plate of the 9V connector. Is that true? When I tried to "crimp" an original 9V wire (cut to length) using an unmodified 9V connector base plate, it was a pain in the butt to get the metal pieces cutting into the wire aligned with the two recesses in the base plate. It appear as if your cutting pieces are bent as well(?). Did you do anything about that or were you just pushing the base plate forcefully into its place?

Thanks a lot,
Thorsten

P.S.: I just clipped the cutting pieces away and walked the soledring way, as @XG BC suggested.

[Unfinished_Projects]

1 hour ago, Toastie said:

But you should mention (correct me if I am wrong!) that you need to modify the "base" plate of the 9V connector

Yes you are correct! I forgot to mention that I bent down the original prongs on the track connectors. Thanks for noticing that!

Unfinished_Projects