cluster connector

You are overthinking this and you have not understood what I posted earlier

POWER for the DASH lamps COMES FROM the TAIL circuit fuse.

It GOES TO the headlamp switch

WHEN the lamp switch is in park or head, that power GOES to the dimmer control

With the dimmer control twisted to the left (brighter) POWER goes through the dimmer control and COMES OUT of the control on the TAN wire from the switch

That TAN wire goes TO the inst fuse in the panel, through the fuse, and OUT to all the DASH LAMPS on the ORANGE wires

So if you checked that fuse UNDER THE CONIDTIONS that I outlined earlier, and you have power on both sides of the fuse, then your trouble IS NOT IN the headlight switch or dimmer control.