C280 radio problem

I have a 1999 C280 Sport with the Bose radio package. This morning when I turned the radio on a loud shriek came out and would not stop. This noise is constant and covers up the radio station (which can still be
heard vaguely in the background). The noise is nearly as loud as the fire alarm in my house. I turn the radio off the shrieking stops.
Any Ideas?
TIA, EJ in NJ
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mmm... sounds like you got EMF problem on the car. Do a test... bring a portable radio into the car... with the car factory radio off... turn the car on and listen to the portable radio... does it shriek too?
If yes, then you got some electrical problem in engine... maybe spark plug wire.
If no, then the radio need repair.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for your reply. I tried my portable and it did not make any noise. Then I went for a drive and the car radio still screeched. After I went into a store and started to drive home the radio cleared up. Go Figure!!
It has rained here for the past three days and the car was outside. Now the weather is dry...perhaps something dried out.
Any other thoughts?
Thanks EJ in NJ
Tiger wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mmm... probably a ground issue. I would sand the contacts clean on the battery... both side and at the alternator if you are handy...
Please keep the battery disconnected when you do the alternator contacts. Use sandpaper to clean it until shiny.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ernie... are you the one whose mechanic changed the battery while the engine is running?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.