[Captain J]

Hi, 2 issues
One, when I drive for an hour or so, and I turn off the truck, it won’t start, starter is slowly turning like with a low voltage battery, but when I leave the truck to cool, it will start again. Any thoughts.
2ed, this wire runs on the front grill, from the left side to near the battery on right side, it’s disconnected near the battery has 2 small glass fuses.
What’s for?
Where it should be connected to?
Pictures attached,
Thanks