Welcome to iRV2 .
I don't know how common the set up on my Freightliner chassis is ; BUT; within 3 feet of the chassis and coach batteries at the battery tray ( rear of the coach ) in the positive cable is a 135 amp fuse , that protects the cable from the rear of the coach to the front, where all the loads attach to a power stud.
These fuses are mounted to the frame behind the battery tray. Would be worth a look to see if your's is similar.
First picture is the frame mounted fuses.
Second is the power stud at the front of the coach, left side with red cable attached. This is the coach battery power , chassis battery is similar on the other side of the fire wall, not visible in this picture.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.