Welcome to iRV2.
Sorry you're here with problems .
Start out by checking the chassis batteries and connections; because from your description you've lost power from the batteries., to the starter and dash.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.