Ringing behind CD player

I have a faint ringing in the cab of my 08 tacoma. I have discovered that the noise is more apparent when I take the CD player out of its place. What could it be? It is like that annoying mosquito ring tone. Does anyone have any advice other than turn up my music or turn on my fan to cover up the noise? Thanks

 

Anyone have advice?

 

gps tracker because the secret service found out your plan to destroy the world

 

Only thing I could think is the radio itself.

 

UPDATE: For anyone who could help, I decided to take off the glovebox and discovered that the ringing was coming from somewhere down there. Can't tell exactly what it is from. It is a high pitch but hard to hear "RIIIIIIIIIING" that bothers me everytime I drive. someone please help haha

 

Well yeah, you took off an area that covers up some of the noise coming from the radio area. If you want my honest advice I strongly suggest you just remove the dawgone radio, start the car without it and see if the noise persists. If it does not, my next suggestion would be to start looking into a quality aftermarket double din stereo.

 

Its not coming from the stock stereo. I unplugged that and it was still there. Its coming from the blower motor area but my blower motor has already been replaced once due to the chirping

 

You might want to unplug that and check it out while the truck runs. Play the process of elimination til problem disappears.

 

It might very well be the blower motor again for all you know.

 

another update: I recently realized that the ringing noise is coming from the ECU. I have not been able to determine if it is from wires touching or the ECU itself. Going to mess with it and see what I can do. Any suggestions?