Nothing comes to mind about the fuse like black piece. Perhaps you could post a picture. I'm sure someone could identify it.

Have you tried turning the dimmer back and forth a few times. It is the same button as the reset for the trip odometer. Many times this will get the lights working again. There not great, even when working correctly, but I have found them adequate.

__________________
Mike

2000 SL500 22,000 miles
1981 300CD 188,000 miles
1979 450 SEL 266,000 miles
2005 Cadillac CTS 25,000 miles