65 Dart Instrument Voltage Regulator Tips

Dimmer controlled instrument lighting. That is a different circuit. Determine if ANYTHING works on the instrument dimmer. You do know? That the dimmer control on the headlight switch must be rotated to brighten them, "turn it CCW."

HOW THAT WORKS

The HL switch has TWO power sources, B1 an B2 at the switch. One comes (unfused!!) from the ammeter circuit and feeds ONLY the headlamps circuit.

The park, tail, and instrument lamps gets power from a fuse in the panel.

The HL switch internally feeds power to the dimmer control, and that dimmer controlled power comes OFF (out) of the switch on TAN. Tan goes TO the fuse panel, TO the small INST fuse, and then branches off to feed all dimmer controlled lighting on ORANGE wiring. So this includes the radio and depending on year, other accessories, shift quadrant, and of course the cluster.

If the cluster lamps don't work, but others do, such as the shift quadrant, the trouble is likely in the harness connector at the cluster, or just the sockets and bulbs themselves

If NO dimmer controlled lighting works, then see if there is power TO the INST fuse. The tail lights must work, the light switch must be in park or headlights, and the dimmer control must be "to the left." If there is no power there, might be a dirty/ burned up dimmer control, or bad connection at the light switch connector.