Hotgrip malfunction

[Buzz]

An easy way check if there are any breaks before/after the point of the cable tie is to use a couple of sewing needle with your multimeter.  Poke the needle though the rubber coating so it makes contact with the wire underneath then use the multimeter points on that... this means that you don't actually have to make a cut in the coating to expose the wire. Move the needles about on the live and return until you find the point of hidden break.  Unplug the grips first obviously!