I've got most of the harness stripped down. I eliminated most of the ECU wiring, all of the Electronic steering, and all of the Fan harness, and the relays for the fan and fuel pump. I Removed the fan and fuel pump relays since I'm going to use a a stand alone set with the GM harness. I'll be using a Lincoln Mark VIII fan which has a big current draw so the stock wiring and relays wouldn't be adequate.
Here's the pile of stuff I've pulled off.
![](http://i.imgur.com/YHc45RD.jpg)
Here's what I'm retaining from the RX8 harness:
![](http://i.imgur.com/Z5rxSkL.jpg)
![](http://i.imgur.com/i2ePMO7.jpg)
The AC Amplifier wire sends a 0-5V signal for the engine coolant temp to the AC Amp. I'm hoping I can just splice the GM sensor since it outputs a similar signal. It's probably not going to be that easy though.
![](http://i.imgur.com/RUPTDbU.jpg)
The Reverse switch wiring is two wires that run through the harness to the ECU harness then through the Engine harness to the transmission. I've pulled them back to the driver fender loom and I'll be splicing on a GM reverse switch pigtail.
![](http://i.imgur.com/aXsvIPU.jpg)
There are 6 wires that go to the Accelerator pedal position sensor. I'll be cutting them off on both sides of the bulkhead pass through. I would have preferred to remove the entire length of the wires but Mazda potted the bulkhead pass through with urethane which makes it very difficult to remove.
![](http://i.imgur.com/et6b4lq.jpg)
The two Canbus wires will likely be cutoff as they will likely be tapped in the cabin instead of the engine bay.
![](http://i.imgur.com/XwRJiJM.jpg)
The two Evap Pump wire will be shortened, rolled up, and retained just in case I need that part of emissions to work.
![](http://i.imgur.com/f6IkVUl.jpg)
The 12V ECU constant will be cut off since there isn't a need for it.
![](http://i.imgur.com/W5XvP5q.jpg)
This one makes me a little nervous. It's a ground from the ECU but I haven't been able to identify exactly where it goes to on the wiring diagram. It'll be rolled up and set aside for now.
![](http://i.imgur.com/ZULab71.jpg)
Fuel pump power wire. It'll be connected to a new relay triggered by the GM ECU.
![](http://i.imgur.com/o37YnLM.jpg)
Starter and AC clutch relay trigger wires come to the fuse box from the ECU
![](http://i.imgur.com/ouboDDd.jpg)
Brake Switch will be connected to the GM ECU
![](http://i.imgur.com/o7dE3mj.jpg)
This is the Cruise control power, signal and clutch switch. They aren't being used right now as the GM computer uses a different method of cruise control signaling. They'll be rolled up and set aside for now.
That's the high level look at what I'm doing on the RX8 wiring. I'll update as I get the GM Stuff finalized.
I also did some work on getting the stock shifter back on. It's about as simple as it gets, a piece of angle with a bolt welded on. It's fairly close to the stock position, but I think it's a little bit taller
![](http://i.imgur.com/W34IO6B.jpg)
![](http://i.imgur.com/dG2q3wX.jpg)