Some of the differences in the Impreza and Forester wiring harnesses include:
- Door harness plugs
- Front harness connections to bulkhead
- Rear harness connections to bulkhead
- Gauge cluster harness
- Forester has hatch components, while Impreza has standard trunk components
While the basic functions, suspension, and many interior components are similar, the wiring is not. So if you are doing an engine swap into the 98-01 Impreza or the 98-01 Forester, you need the bulkhead harness that matches the chassis. (ex: Impreza harness for Impreza chassis).
Additional note for 98s: For both the Impreza and Forester, 98s have unique harnesses for those models. To replace a 98 Forester harness, another 98 Forester harness would be needed; the same applies to the 98 Impreza. 99-01 Impreza can be interchanged within Impreza models, and 99-01 Forester can be interchanged. Also, keep in mind that the 02 Forester still uses the older interior, but the harness is also unique to that model and year.
Additional note for 98-01 Impreza: Bulkhead and front harnesses from the same year can be interchanged, as the only difference is the rear harness between the sedan and coupe. Just be careful not to mix up auto and manual options, because those are different, and "L" models compared to "RS," since the RS has a sunroof and ABS while the Ls don't, and they aren't provisioned for those features.
