Sounds like an interesting find for G owners! I'd just watch that battery!!! With the car off and radio + radio amp + carpc on for large amounts of time, that just calls for dead battery situations.
So this was one of those great accidental discoveries, right up there with penicillin. Anyway, this hack allows you to turn on your factory radio when your car is off, you don't even need the keys.
So I wired my car like this: S1 and S2 are switches
The purpose of S1 is kind of like a valet switch, when it is off nothing gets power
S2 is an override that allows me to turn the PC on without turning the car on.
S2 does nothing if S1 is already switched to the off position (duh)
I spend about 95% of my time with S1 on and S2 off, as that makes the opus make all of the Startup and shutdown decisions.
I had my DMM out when doing all of this wiring so I was checking voltages. My Cigarette adapter only gets power when the ignition is on. So I run the 12V from the battery and check the voltages, the switch is doing its job.
I then Hook up S2. When I flipped that into the on postion I can hear faint white noise coming from my speakers. I thought it was weird. I thought it was just ground loop noise or something. I didn't look at my radio to see if it was on, it was set to SAT with no input so thats why there was no music coming from the speakers. The noise made me think I was going to have to put a diode in the circuit to keep the voltage from going up the cigarette lighter
Anyway I leave it as is and put the car back together. When The computer was hooked up and the DMM was put away, I played with the switches some more. Flipping S2 on turned on the CARPC And the Car radio!!! The Cigarette adapter must be on the same fuse as the radio or something. Anyway I can turn my radio on with this switch without even putting my key in the car. No other accessory functions turn on (wipers, turn signals, power windows, seat heaters, AC) Just the radio.
This was the coolest accidental hack ever. I only tried it on the Cig-adapter in my center console.
Am I going to fry my opus by putting that much power into it?
here is a few pics of the implementation
No center console lid on:
It would be cool If this works on other infinitae
I am aware of the limits of the battery. I was able to run the PC with sound for about a half an hour and there was no trouble turning the car on. I think the G's have a very high capacity battery because you can move the power seats all you want and the battery never gets tired.
I have found that if you flip the S2 switch on, while the car is running, and the headlamps are set to auto, and its dark out, and you turn the car off, the headlights do not turn off automatically. Minor drawback... Once you flip S2 off, the headlights are on the normal 60 second delay.
The car radio coming on is because you powered the entire IGN line when you hit S2. Instead of the SPST switch to connect the two, consider using a SPDT switch to control the IGN on the Opus, like this:
That way, your Opus can turn on, but you don't mess with any other electronics.
I had thought about doing it that way, or adding a diode, but i like the functionality that this creates
The only electronics that get affected are my radio (which is a plus) and the auto headlamps (I don't care)