A:Answer Hello Al! We strongly recommend rewiring even though there are some functions similar to the CDXC7000X unit which came out back in 2000, the CDX-G3205UV has certain connections are wired differently which requires to use the supplied harness. For details regarding the connection, please check page 27 for the CDX-G3205UV using the following link: https://docs.sony.com/release//Manual_4595967111.pdf and for the CDX-C7000X: https://docs.sony.com/release//specs/CDX-C7000X_Spec_Sheet.pdf ~Jeannette