64 Dart cluster connector

It is keyed to fit only one way. If your temp and fuel gauges worked before and not now then the path to ground thru the different sending units Could be the issue. I would verify 12 volt power to the regulator on the back of the cluster. Beyond that regulator it is not a constant 5v reading due to regulator style but also a voltage source below 5 volts can be used to test those gauges to verify they move. After that it’s a deeper issue, but could be sending unit related.