A strange sound has appeared in my left rear speaker when the radio is turned on. It's a loud rattle, independent of what the radio plays and unresponsive to the volume control. Engine does not have to be running and it's not related to engine speed anyway. I have a mechanical fuel pump.

Here is what it sounds like:

https://www.dropbox.com/s/w8tygn3bgq...attle.wma?dl=0

Any idea what it is? Is it even related to the radio (stock am/fm cassette).

 

I would say its a blown speaker. But, it is too rythmic from what it sounds like. When I have had blown speakers it is more like a popping static sound

 

check your connections on the back of the speaker. I had a sub that had a loose one once, and it sounded just like that. it was just touching the terminal, so it make the popping noise with bumps, etc.

 

Blown speaker or output IC. Try a different speaker first and report your findings.

 

Thanks, I'll check the speaker. Hope it's only something like that. I did some searching and saw this kind of sound identified as "motorboating" caused by something going bad in the radio. Fixing something like that would be beyond my expertise and I'd probably go looking for a junkyard replacement radio. I want to maintain the stock appearance.

 

Well, I tried another speaker. Same thing. So that's not it.

 

Probably a bad output IC.