Connectors

You need a factory service manual instead of the usual 2 page aftermarket diagrams. You can get either at MyMopar for free. Just look over the diagram for the same pattern as the connector and same wire colors. Another clue is the area "where they are" near the radio, the heater, etc

In your case I don't think MyMopar has a complete 71 Dodge manual, you'll have to settle for the 71 Plymouth chassis manual