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If your Jeep owners manual says to disconnect the battery then you should disconnect it.
You can , hook the brake buddy direct to the battery on an independent circuit , or run a power and ground from the coach .
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.