There is also a LARGE fuse in the inverter supply cable , 300 amp probably , above the batteries , that maybe in trouble . Check that you only have 12 volts at the connection before you replace the fuse if required.
NOTE: If you do have the fuse blown , pick up a couple when you purchase them ; they are not available everywhere.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.