I am sure this is well documented some where but my radio reception is completely fine in the FM band and Varies from fine to horrible in the AM band as I hit road cracks, potholes, the curb, Just kidding about the curb...Anyone know what is the root cause of this intermittent radio reception? I suspect it is a connection for just the am antenna some where in the car. I believe there are two antennas for AM, one in the rear window one in the rear bumper? Anyone have the fix?

It's a well documented problem. For my 2000 S80 T6 it took four (or more) trips to the dealer where a variety of fixes were tried. On the last trip the service manager showed me a copper strip that Volvo had released to correct a poor ground connection. It's been 2 years now and AM reception has stayed constant. From Washington, DC I can get AM stations in Cincinatti, Vancouver, etc. The Volvo radio is no DX machine, but the audio quality and signal strength is decent. However the directional window antenna does not perform nearly as well as an omnidirectional whip antenna around tall buildings.

I've had the exact same problem with the same car. First complaint to the dealer was "resolved" under warranty. They told me that they replaced the antenna amplifier that was bad. I thought this was stupid since the poor reception came and went with bumps as you described. But they were ripping off Volvo, not me (warranty) so I didn't argue. The problem did go away for almost two years.

When the problem came back (out of warranty) I went back to the same dealer and said that this is the same problem that I had complained about under the warranty, and I don't want amps replaced (my money now), I want the bad connection found and fixed. They immediately said that this was a known issue fixed with the installation of a copper washer at the connection (no specifics) - no charge. So far it's been about a month and the reception is perfect (or at least as good as it's ever been - no changes on bumps big or small).

brt;

If you search the archives of this site and vvspy.com I'm sure you will find plenty of info on AM reception.

Rich

Even at its best the AM reception is poor due to lack of a proper outside antenna.
There is a chronic problem with poor contact at the RF amplifier connectors located in the right rear fender cavity (accessible from within the trunk by removing a trim panel) and the left rear "D" pillar (accessible by removing the trim between rear and side window). Usual dealer fix is to rotate and re-seat the connectors, which lasts for a few weeks.
The most reliable "fix" is to carry a $5 battery-operated am radio in the car, and just use the factory radio for FM and CD.