60amp fuse blown on deep cell caravan battery

Hello, please help if possible - just away for the weekend and found that the van's battery would not charge from solar panels. Checked panels and they are ok. Got home and tried to charge from power without success. Before taking to auto electrician we thought we could ask if anyone has some clue why the battery fuse would blow? The road we travelled was gravel and full of pot holes. We found that a L1 red wire had come apart from back of fuse box too. Could either of these be the cause or would there be something more sinister and expensive.
Any help much appreciated :-)