As promised...



I ran into a little snafu initially, I didn't realize that the 555 required a "pulse" for the trigger meaning that if the power went from high to low and didn't go back high it would "continue to trigger" meaning the LED would stay on...

I got around that by adding a simple "RC" circuit to the trigger... now it works as designed.

There are essentially 4 wires that connect to this circuit
-12v constant (from the batter)
-ground
-12V switched (the accessory wire) and
-the LED output signal

if you look at the picture you can see the red and black wires up top... power and ground. the big loose orange wire is the "accessory" which I would switch by simply touching it to power and the unplugging it to simulate the car turning off. and the LED I attempted to visually separate from the rest of the circuit a bit.

you can mount this somewhere in the dash and run two wires from the output, one to each door to act as the power signal for the LED... the ground for the LED can just be grounded to anything metal in the door.

If I still had a working video camera I'd make a short video showing it in action.