[Tim]

Thanks to everyone who has helped with this.
I have managed to strip about half an inch off the insulation of the centre core and find the broken end. I now have enough to solder to, and with the help of croc-croc leads and PP3 battery connected to a Y input have established the correct connections.
The line itself is a screened plastic tube containing a pair of thin uninsulated wires( bi-filar wound?) wrapped around a stiff inner core.
I would like to seal the end of the line with something to hold the bare wires in place during the handling and soldering process.
Silicone sealant springs to mind. I understand it is a good insulator, but all I have is the standard acid cure variery( with the vinegary smell-Acetic acid presumably).. Would this be suitable?
I might be able to manage some paraffin wax.