I've got a 2001 ML 430 with about 150,000 miles on it. Having a problem with the FM radio unit. Can barely hear the volume on it. Volume on the Weatherband, AM, and CD (Cassette may be dead or dying because I'm getting the Tape may be wound too tight message) is fine. I've searched various forums and the answers seemed to center around blown fuses or FM amplifiers. I've got no clue. Any help would be appreciated.

I would look at the amp

Thanks Gullwing. Where in the vehicle should I look to find the amplifier?

Ummm I don't remember it has been a long time since I looked at one.

amp is in the rear door.

Depends on what amp people are talking about. antenna amp is located in rear tailgate under the panel. The audio amp is located under the drivers side dash, mounted to either the quarter panel or firewall (i can't recall at this moment). I have found that when everything else works but fm volume, it is generally the headunit, just my experience though