Gillan

After identifying several suspicious mods on my auction daily G37, I just now realized that everything on my center console doesn't work. This includes all radio, climate control, and infotainment screen functions (screen doesn't turn on at all, it just stays black all the time). Also, the AC is blowing when I put my ignition in the On position and I can't turn it off because the climate control buttons don't work. In fact, the only button that works in this area is the one that turns on my hazard lights. I took off the assembly and checked the wiring, all the wires and connections were plugged in properly and looked completely fine and undamaged. Could this be a problem with some fuse or relay, or is it a problem with the circuit boards that I've been reading about in other forums? How do I even figure out what is causing this problem? If it is a problem with the circuit boards, what would be my best option in rectifying the issue? Last question, would replacing the entire assembly fix my issue or is there something else that might be the cause?

UPDATE: I decided to check my fuses, so I disconnected the negative battery terminal and used a digital multimeter to check the continuity in each of the fuses starting from the driver's footwell. All of those were fine, so I moved onto the fuses under the hood next to the battery where I found a blown 15a fuse that was labeled 'Audio'. I replaced it with one of the spare fuses located in the drivers footwell, reconnected the negative battery terminal, and put the ignition in the on position and now the center console works! At last I can put my AC compressor to rest since I was unable to turn off my AC all this time :/

mummy2

Check all the fuses first. You'd be surprised the random number of things that are managed by one fuse.

Gillan

Should I check the blue relay-looking things that sit beside the radio unit? Or is there a fuse under the hood that I need to check?

13_SkylineSedan

There are two main fuseboxes. One is near the driver's left leg and the other is awkwardly mounted on the firewall behind to the battery. Always begin diagnosing electrical issues by checking fuses. The answer is often the most simple one. I'd start with the easier box near the driver's leg.

If you want to do some homework, look up the factory service manual called PG.pdf (power and ground) over here:
https://www.nicoclub.com/infiniti-service-manuals
Click on G35 / G37 / Q40, click on G37, click on your body type, click on your year, click on "Power Supply, Ground and Circuit Elements", scroll down in that window and look for "Click here to download a copy". Schematics, wiring harnesses, connector pin-outs and wire colors - it's all in there with some digging.