Rallye Instrument Panel

Yes and a grounding pigtail SHOULD be added.

Here is how the dash lighting, controlled by the light switch dimmer, works

The light switch has TWO power sources

1, B1, comes direct from the "welded splice" in the ammeter circuit to supply ONLY the headlights, which has a breaker built in/ on the light switch

2, B2, comes from a fuse, and powers the park/ tail lamps AND the dash lamps. That power goes through the dimmer control, OUT the switch on TAN, back down to the fuse panel to the INST fuse on one end of the panel, and out to all dimmer controlled lighting on ORANGE wiring.

So the tail/ park circuit fuse must be good and supplying power, the tail lights must be getting power, and the switch either in "park" or "head," with the dash dimmer twisted to left. Vigorously twist it back and forth to clean the rheostat, and wiggle it to see if there is a "sweet" spot where it makes contact. Measure for voltage there at that INST fuse to see if it is getting power