I have a 2007 g35s sedan and my radio and ac stay on constantly. Whenever I go down the road they will sometimes flicker on and off. Sometimes just for a second and other times it could take minutes. Whenever they flicker off I can hear a little clicking noise under the dash on the right side of the steering wheel. Does anyone have any idea what it could be.

When you say AC do you mean the AC compressor or the fan blower motor?

it’s the ac controls I tried replacing the acc relay but I still have the same problem

Just to verify, the relay you swapped was the one mounted on the BACK of the cabin Fuse Block - J/B right?

How many relays do you have on the back of that fuse block? I would number them individually with a sharpie and start swapping them around just to verify you got the correct one, there will be 2-4 relays depending on your exact vehicle, my 2006 coupe has two.

If that doesn't solve the issue then it's probably the key switch itself is not actually turning off for some reason. Or someone has messed with the wiring behind the dash so it's getting powered from somewhere else.

Yes and I have 4 back there and I tried swapping them around but still nothing

Those relays get their control power directly from the ignition key, try pulling the fusible link M fuse (40 amp). It sends power to the ignition key. If that fixes the issue your problem is likely a failing key electrical switch which I THINK is replaceable separately from the actual lock cylinder. That harness is held onto the back of the lock cylinder with a single screw on the back (not the little black box on the side which is the RFID antenna).

Err wait, I just realized you have a 2007-2008 sedan, does it have the intelligent key push to start system?

Yes

Ok so basically the V36 chassis has those relays turned on by the BCM, if they aren't turning off when the vehicle is off, and you ARE ABSOLUTELY SURE the problem isn't a sticking relay, then it's a BCM issue.

I would go down to Autozone and buy another relay, try it out, just to verify. You might have multiple relays that failed in the closed position, at least throwing a new relay into the ACC slot will increase your chances it's not a relay issue.

The BCM controls turning those relays off and on, not the ignition switch like the V35 chassis.

I would definitely schedule a 1 hour diagnostic with Nissan to verify this before tossing in a replacement BCM though. Worth the $150 for a 1 hour diagnostic, just tell the service manager EXACTLY what the problem is and that you want the BCM tested.