Hi
The dash lights are fed by the headlight fuse ( red/yellow wire )
The meter including the tacho by the backup fuse. ( red/green wire )
However, both are in the 16 connector plug & socket under the left hand infill panel which can be prone to the elements.
I'd check there first, check for corrosion, clean the contacts & coat with dielectric grease.
Goodluck
Meant to add that the neutral light has a different feed to the above so would still work.
The dash lights are fed by the headlight fuse ( red/yellow wire )
The meter including the tacho by the backup fuse. ( red/green wire )
However, both are in the 16 connector plug & socket under the left hand infill panel which can be prone to the elements.
I'd check there first, check for corrosion, clean the contacts & coat with dielectric grease.
Goodluck
Meant to add that the neutral light has a different feed to the above so would still work.