Here is some backstory. I posted to Reddit but i feel like member here have more specific knowledge if Nissans.
https://www.reddit.com/r/Cartalk/commen ... _turn_off/


The problem: When all of the fuses are in place, i can start my car and it runs and drives fine, however when i turn the key and remove it, it continues to run.
Other symptoms: When driving, i notice that the Radio has no power (aftermarket, came with car), the dash lights don't come on for night driving, and the 1st gauge on the dash does not turn on and has no information (the electronic one you can cycle through)

I found that if i remove the A/T Cont fuse in the IPDM, the car will turn off. But as soon as i put it back in, it does not turn off again. I believe that stands for Automatic Transmission Control, but at first i though it was Anti Theft. I have been trying to go through the wiring diagrams in the maintenance manual here, but i cant seem to find the right circuit. Ill post a picture of the IPDM to show exactly which fuse


Picture of interior with Radio and Gauge not working (outlined in Red)



Picture of the IPDM fuse which when removed, allows ignition to turn off

If there are no other mods to the car, and it's not a flood / fire salvage, someone royally screwed up the radio install.

I'd find a stock 350Z radio and install it. When you do, I'm sure you will find some janky wiring behind the dash.

Considering it is involving the ignition, the lights, the driver info gauge, and the radio, it sounds like there's an issue with the alarm / anti-theft wiring.

Start tracing wiring (visually), beginning with the radio.

Other options:
If the ignition circuit going to the ECM sees power (typically 5 volts or more) when the ignition key is turned off, the car will keep running.
Check ignition circuit pin at the ECM for voltage with the ignition key turned off.
If voltage is found, remove the fuse for the BCM and the TCM one at a time, and see if the engine turns off.
If the engine does not turn off, and there is still 5 volts or more on that circuit, check for a short to voltage (it's getting power from SOMEWHERE). If the engine does turn off when pulling the BCM or TCM fuse, replace the module that caused the engine to turn off with the fuse removed.

AZhitman wrote:If there are no other mods to the car, and it's not a flood / fire salvage, someone royally screwed up the radio install.

I'd find a stock 350Z radio and install it. When you do, I'm sure you will find some janky wiring behind the dash.

Considering it is involving the ignition, the lights, the driver info gauge, and the radio, it sounds like there's an issue with the alarm / anti-theft wiring.

Start tracing wiring (visually), beginning with the radio.

I will do that. I already found a LOT of questionable wiring jobs, so i would not be surprised. Should i just be looking for wires that are grounding? Or something else in particular?