From looking at the WSM wiring diagram, there are two 5 amp fuses feeding the dash panel.
One 5 amp fuse is fed from the Key switch ACC terminal and the second from the light switch.
You might also try unplugging and re connecting the multi pin connector for the dash.
Pin #40 in the multi pin plug is the only ground for the panel except for the low oil pressure light. Use a test light and make certain there is a ground on the harness side of terminal 40.
Dave