2005 S80 with an Eclipse Nav system; AM radio reception was a rather loud whine with the ignition on. (Actually, it was with the ignition off also, until I had a better re-installaion done and could determine that it was caused by turning on the ignition switch.) The noise was not timed to the engine or acceleration - it was a steady whine with the switch on.

Solution:after many tries with Volvo Service department, original installer, etc., another radio shop placed either a resistor or regulator or the like on the rear window antenna amp. They said running at 5 amps with the switch off, and 14 with it on was causing the problem.

There were a lot of people involved that should have known this about Volvos (Volvo Service department comes to mind), but I am entering this for anyone in the same boat in the future.

 

Thanks for the information.

 

i think they make a sound reduction kit which is inexpensive and would have solved the problem too i believe