Well, nice weather this morning, so got to this cable junction box.
You have to remove plastic covers from front and rear of seat rails to expose triple square bolts that you then remove the fronts and loosen the rears.
Slide the seat back all the way and tip back until it rests on the rear seat.
Now pull up the front carpet and foam until you can see the box nestled to the right of your right ankle when it is on the throttle peddle. It is behind a black aluminium shield that takes 2x 10mm nuts to remove.
Then you unclip the plastic over the opposite edge to the 2 x nuts.
I opened mine and it was a mess, looks like it has been hot and sooty and white powdery residue, even the carpet foam is singed where the thick cable comes up into the bottom. I doubt it will catch fire, but is a massive design fault/ QC problem that existed from the factory.
I think when the battery is low, the charging from the front 180A alternator and consumers will overheat the cable, and cause a low charge voltage - that is why we have so many battery issues. Then in reverse, when trying to immediately restart the car, the already hot cable has too much contact resistance and just gets hotter and hotter so not enough current can get to the starter from the battery in the boot.
Still wondering what to do at this stage, I guess cut off the heat shrink...
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