How come the engine cranked OK, but later you decided that it was necessary to replace the cable to the starter and the battery ground?
If the negative wire grounding the battery to the chassis became heated to the point where the insulation, battery tray and battery housing were damaged, a very high current short circuit must have occurred from battery positive to ground.
Everything indicates a substantial short to ground in the lead to the starter, or within the starter. Please advise exactly why you replaced the cable.
You advise that all fuses including the main fusible link remained intact. Therefore the only other possibility is a short circuit at a point in the main battery lead before the fuse box, or within the fuse box bus connections, before the fusible link. A burnt out connection within the fuse box could be the problem, but it is difficult to comprehend how a direct short to ground within the box could be likely.
As you have not mentioned anything, one must presume that all things electrical are OK and presume that the engine cranks OK except for “engine start up“, i.e. the engine will not start/run. Do the fault indication lights illuminate as a test function, as is normal when the ignition is turned on? Are all electrical items functioning normally?
