1972 Duster Build with my Daughter
If the 2 black ground wires for the headlight harness come out of the tape just in front of the battery tray, they should bolt to that bolt hole in the rad support, upper drivers side left. There should be an additional ground that comes of off your negative battery cable that bolts to the same place. Trace the biggest connector onto the rad support with a pencil, and then go to bare metal underneath it with silicone grease under the connector to keep it from crudding up. Those are important grounds.