65 Valiant high beam indicator not working

My 65 Dodge wiring diagram shows a double red wire coming from the bulkhead connector to the dimmer switch and to the high beam pin on the instrument cluster. If the high beams are working through the floor switch, then the issue is either the wire to the instrument cluster connector, a bad pin at the connector, a bad trace on the circuit board to the bulb or possibly a bad ground (least likely if the cluster lights are working) Hope this helps