An alternative was to repair 9V connectors

[Dav1d]

I have used the recommended way to repair 9V connectors. You need three hands to take the connectors apart and occasionally the small triangular metal connection breaks and sometimes you need to have a second go as the metal connector hasn't pierced the insulation. But I have found two out of three work successfully.

I have a Airport Shuttle and with age the insulation is deteriorating and breaking off, therefore I decided to try repairing the insulation, rather than taking it apart. 

I used Waterproof Liquid Insulation Electrical Tape - Waterproof Liquid Insulation Electrical Tape Fast Fixed Dry Glue Sealing U4S4 | eBay

The example image they show doesn't look neat, if you take care you can make it better.

I was at a show this weekend and it has worked successfully, running for the two days.

      

[1963maniac]

I have used the liquid insulation. It does make the wires good again but with the same reservations as you cited. I don't know what this means "I  have used the recommended way to repair 9V connectors." But these videos helped me get to a much higher success rate. As a beginner I made a dozen before I had to do one over. The wire that "BatteryPoweredBricks" uses has very soft insulation and is very pliable. The wire makes the difference!!  The brand name is "BNTECHGO". You want 24 gauge. I bought 6 "pin" width. It can be easily split down to whatever number of wires you need. Search Battery powered bricks channel with "wire repair" for more 9V system tutorials. There are at least 9 helpful videos. These are highly recommended!

 

[Dav1d]

Thanks, I used this method - this was the "recommended method" - but this is a simple alternative method that has worked.