Sometimes when I turn my truck off or when I turn my radio off when my truck is running there is a brief buzzing sound that souds like it is coming from the back of the radio. The sound can be compared to something 'like' a short deer grunt (I know that is stupid but, I couldnt think of anything else it sounded like). I have the single cd player. Anybody ever heard this in their trucks?? Until my radio dies on me or the sound gets worse I am not really going to worry about it. Truck has 70,000 miles.
Thanks, Jason

 

I have the same thing, sometimes and not always when I fire up the engine I can hear a buzzing----it sounds like it is cycling---buzz pause buzz pause ??? havent a clue, figured its probably the stereo freaking out ?

 

I have the same problem and believe it to be EMI/EMC issues. My cause is from putting my cell phone in the dash cubby. Once I move it out of the cubby and place it on the floor console or seat console, problem goes away.

 

expressfish - yours sounds like this. Not sure about the other 2.

http://dodgeram.info/tsb/2006/08-002-06.htm

 

Sure sounds like RFI from the SPARK PLUGS to me....

 

I agree with MiGunner. Cell phones are a common cause of this problem. When they're places in the cubby's near the radio, they cause RF interference entering the electronic components of the radio and it's antenna. My old F150 with Alpine stereo did it. My Volvo does it and my new 2500 does it when a cell phone is put in one of the cubby's near the radio. I now keep my phone in the floor console... no problems there. It seems that you need to be about 12-18 inches away from the radio to cure the problem. Try putting your phone in the door pocket, I bet the problem goes away.