Okay, I'm screwed. I did a lot more testing tonight. Bad news, unplugged the amp, and the noise is STILL THERE! Ugh. At this point, I am sure it is safe to say it is not an issue with the radio or a noise coming from the speakers. Here is what I found tonight.
- Noise is very noticeable on startup. It is not there when turning over, but the second the engine ignition, the noise starts.
- Sitting in park, and fluctuation the throttle changes the level and pitch (not consistently) of the noise.
- Cruising at 50, and manually controlling gears makes it very easy to reproduce
- It is very easy to hear the noise when shifting into 5th gear from 4th.
- The noise is almost gone when in gears 1-4.
So... I am not sure what to make of this. I swear it sounds electronic, and I think it is voltage related. Which is why pressing the throttle changes the noise.
The good news, my iPhone picked up the noise. Please someone tell me you can hear it!