Welcome to iRV2.
If you don't blow the fuse during operation of the leveling jacks ; but it does blow when your driving the coach I would suspect that there is another load on the fuse .
Do you have any info from HR giving the correct fuse size for that location ?
Do you know the leveling jack manufacturer ?
Are you aware of any 12 volt system that quits while you're driving?
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.