so a few years ago i looked into the "Big 5" or "Big 7" upgrade i think its called? Pretty much replacing all the major battery wires with a bigger gauge. Worth looking into?
If yours are looking a bit ratty, I would, for the money. Juice is only as good as the cables that carry it. I reworked my electrics when I purchased my LJ last year, went with this kit but others are available.
https://www.ksuspensionfab.com/store/p105/TJ_Ultimate_Power__/-_Cable_Upgrade.html#/