I have an 01 A6 2.7 T. Everytime I put on my rear defroster I get horrible radio interference, whether on A/M or F/M (Bose). As soon as I turn off the defroster, the noise ceases. .

Maybe a bad or loose ground, faulty or sticky relay???

Any ideas or possibleremedies would be greatly appreciated.

 

The FM antenna connections are right next to the rear window, take off all that trim around the rear window and see if something is loose or fallen off somewhere.

 

Another thing, if it is like my a4 the antenna is built into the window. If that is the case it will cause interference because of the voltage running along the antenna.

 

Have you had any luck fixing the interference with you rear window defroster and the radio? I am just curios because my 2000 s4 is doing the same thing and I don't know where to start figuring it out. Any help would be appreciated. Thanks!

 

Everytime ive run into this its something internal to the windshield itself. You may want to try cleaning the windshield to make sure there isnt some glue from a temporary tag causing a short between the antenna and the defrost circuit. Just be carefull not to damage the wiring on the windsheild.