Turns out the wire was broken
Or
The wire was so old and exposed to the elements it was scrap for about a foot along

So I tried to find some pounds the same size but no luck so I simply inserted new wires into the old pins, a bit of heat shrink and solder and then a rubber pipe around the outside before fitting some plastic on top

The wire is so exposed and sits right next to the got side of the AC pipe that it was only a matter of time

But now it's fixed and ice cold again, thanks to a free top up from Kwik Fit the other week

But in other news, the magnet on this unit is fixed and not removable so my £15 replacement pump was a waste of money