If you are lucky enough to have a complete and intact wiring harness, then the restoration process is relatively straightforward. First, all of the old insulation must be carefully removed. This can be done with a wire brush or a rotary tool fitted with a abrasive bit. Next, all of the exposed wire must be cleaned with a wire brush or a rotary tool fitted with a buffing bit. Once the wire is clean, it can be coated with a clear lacquer or enamel to protect it from further corrosion.
If your wiring harness is in poor condition or is missing some pieces, then the restoration process becomes more complex. In some cases, it may be necessary to fabricate missing pieces from scratch. This is a time-consuming and difficult task that should only be attempted by experienced enthusiasts. In other cases, it may be possible to find replacement parts from a salvage yard or online supplier.
No matter what condition your wiring harness is in, the restoration process will be time-consuming and require a considerable amount of patience. However, the end result will be a wiring harness that looks and functions like new.