Exactly what I was trying to sort Jack, WHICH cable was replaced...
The fat one from negative goes to the chassis and then to the gearbox, but on the positive terminal, one goes directly to the starter and another (a bit thinner) goes to the distribution (fuses & relays) box.
We definitively need to know which one was replaced, I'm afraid a picture of the battery and surrounding won't help much, unless it clearly shows a burned cable/connection, which I doubt...
Best regard, cheeers, Bernie