Dash light relay??

OK, in the fuse box there is one fuse separate from the rest (electrically) for the instrument lamps

The lamp dimmer on the headlight switch RECEIVES power from the tail lamp fuse, so the tail fuse has to be good FIRST

When the headlight switch is in either "park" or "head" the dash lamps can get power IF the dimmer is turned to "some brightness" maximum being twisted towards the left

That is the only time the instrument fuse is powered, as that fuse RECEIVES power FROM the output of the dimmer (tan) and then sends it out to all the dimmer controlled lamps on the orange wiring.

So that is about the first place to check, as it's a central point, and easy to get to.