1965 MMP's Barracuda Hemi swap! The Ever Changing Build
I'm using a Bouchillon performance kit with and unlocked 08 Jeep ecu. It's calling for the two wire (start) and (run/start) and I'm guessing its for the same reason my Fitech on my truck needs it. There is an interruption of power between the two keyed positions. I'm guessing the efi system isn't going to work with this interruption and why it needs keyed constant power. !?!
Makes complete sense that the PCM can't see an interruption of power between the 2 key switch positions. Needs to see that the key is on in both or it will not fire the injectors and coils.
I had planned to just tie the brown and blue wires together but there is a moment between the 2 positions where neither has a connection. So I plan to use an F-Body ignition switch since it bolts in and the blue wire is powered in both positions. Requires me to change my plug under the dash or something as the F-Body plug is completely different but I will cross that bridge later.
I wonder if your run/start wire is the one signaling the PCM to ground the starter relay. That's how the '06 diagram I have shows it, there is a wire running to a pin on the PCM that is powered only in the key start position. The '08-10 wiring diagram I have doesn't show a similar wire but I think that is because PCM get's a signal over the CANBus network in those years. The '06 diagram shows it as pin 30 on the c1 connector. Is that where the run/start wire you need to wire up connects?
Do you have the PCM controlling the starter relay?
I can see it working to use the brown wire to power the run/start wire plus the run wire and then use the blue wire to power the run wire but block the run/start leg using the diode. At the same time, the yellow wire could power the run/start circuit while the blue and brown wire could power the run circuit, provided there wasn't a momentary break in the switch where neither blue nor brown is powered as the switch changes position. That would remove the need for a diode, right?
One workaround for the ignition switch dropping the connection between the blue and brown wire is to only use the key to turn the car on and then use a start button that sends power to the C1/30 pin. Nice thing is, if the PCM is controlling the starter relay, there is no danger that the start button will do anything once the motor is running as the PCM will ignore it at that point.
