iWire Turn Key 818 Harness for R and S Models

[iWire]

Any plans on modifying factory harnesses to work as stand alone factory ECU? With just a power ground and switched lead coming off for hook up.

I can definitely build that if anyone wants it. I've done similar setups for VWs and Porsche's that already have the body side of the harness. It's not quite that simple since there are some inputs/outputs left over. Off the top of my head the leads that would be left over to hook up are:
Battery power
Ignition (Key on) Power
Starter
Cluster inputs (VSS/Tach/CEL/Coolant/Oil Pressure) - I could also wire up the cluster as part of the build if you choose
Radiator fans (ground side trigger to a relay from ECU)
There are probably a few more that I can recall at the moment, but that's the basic setup. You would still have to figure out how you want to run all of the body functions like headlights/turn signals/illumination/etc. This is no easy feat unless you are running the bare minimum to be able to get away with a couple switches to run things. It will also get a bit more clumsy/messy unless you tie into the fuseboxes I use to run the engine.

my friend and I decided to try and tackle just building the harness ourselves from scratch. definitely time consuming, using one of my garage doors to post all the diagrams on. From what I noticed, there are very few actual fuses in the main circuits you actually need, kinda crazy to think about. I would also have to say Subaru's diagrams kinda suck imo. Now that we got it going, seems a lot easier than trying to make the stock harness work as it was. My only worry is if we might have deleted something critical for the ECU to function, flash, etc. since we deleted so many things, hopefully it all works out! We basically wired in only what we needed to control the engine and cluster basically, everything else such as lights, etc. we put all on their own separate circuit controlled by a switch panel, is there any issue doing it that way?

It may work out OK. I use a combination of both factory and new. I cut out everything that isn't related to the engine and run fresh wire for everything body related while reusing plugs as needed.

I'm doing something similar and I left behind at least 75% of the factory wires. Keep in mind that I'm keeping cruise control, radio, all the switches on the steering column, and wiring in heat/defrost.

The biggest problem with the Subaru diagrams is that they leave out anything not relevant to the system that's on that page. There's a bunch of cases where it looks like a wire only goes to one place but it really goes to many places and you have to look at several diagrams to get the whole picture.

My strategy is to cut all the grounds apart and run them to a local chassis point when I install. I also cut all the power supply wires to each system so I can use a single smaller fusebox. I left as much wire as I possibly could, but I ended up extending many of them. The only devices I have under the dash are the high beam and daytime running light relays. Everything else is under the engine cover. I don't like working under dashboards.

My guess is that will be a bit tough to do this way. The end result will probably be a fusebox area that is the same size because of the number of fuses required for both constant and ignition powered systems.

Hey I am r spec!

Hahaha! You are the harness. I need to come up with a better name for the harness since it works in both Rs and Ss.