Unfortunately, this situation does come up from time to time with our 1967 Chevy Impala, Super Sport, Caprice, Bel air, and Biscayne owners. Believe it or not, there were actually a fair amount of early 1967 built cars that escaped the factory with mis-indexed original rear body harnesses. The assembly line workers at the various assembly plants would just swap the wires at the fusebox area to make everything operate properly. However, at American Autowire, we build all of our harnesses to the latest revision of the OEM engineering drawings, which were corrected very early on in the production process to alleviate this deficiency. Therefore, there will be a few of these anomaly cars out there that need the wires in that main connector switched to make the harness and vehicle operate properly.
If you run into this situation, contact our tech support staff at 1-800-482-9473. They may be able to help you do a field repair, or assist you in returning the products to us so that we may make the change for you here and send the updated harness back to you right away.