Car is a 2007 Maxima.

I get this ringing noise that almost sounds like a door chime that is on a low battery. It does it if the car is just sitting with no key turned on. It makes the noise if I leave the car sitting for multiple hours and come back. I can unhook the battery and the noise goes away.

Looking under the hood facing the back. On the left side there is a set of fuses and relays. If I remove this one in the picture the noise gets louder.
This fuse is labeled Throttle Motor.



If I put that fuse back in and pull the relay it gets louder. I do not know what the relay is because it is not marked.




If I unplug both at the same time it gets loud. If I plug them both back in it gets quieter. I have taken a metal pipe and tried to locate the ringing but the ringing is such a high pitch I am having a problem locating it.

Now the odd part if I pull the fuse inside the car on the inside fuse panel labeled Electronics parts the noise goes away. Now here is the funny part I can still crank the car and it runs fine. Although I have not tried to drive it down the street. All of the lights, blinkers, radio, gauges, and anything else I could click a button on works.



Any ideas what this could be?

 

Pulled all power to the car last night and left it. Put the power back on the car this morning and the ringing was gone. Came back in 30 minutes and the ringing was back.

Any ideas?

 

Wondering if you figured this one out... I have a 2004 that won't start. It's making a similar noise, but only when the key is turned to the 'on' position. I've pinpointed mine to the TPS.... when I remove the sensor, the noise stops. But the TPS voltage values are all normal as far as I can tell.

 

Based on another thread, I'm thinking mine might be a normal noise... just never noticed before.

 

Further trouble shooting found that the sound was coming from the alternator. Ironically it has not done it in a week or so. The odd thing about finding out where it was coming from was how we found it. A friend had his hand over the area but in the air and moved his hand around, it changed the pitch. So looking further into it the alternator was making the noise. So we think it may be a bad diode. I am going to rebuild the alternator so that should fix the problem.