I've posted this issue on Volvo Forums too, and am totally stumped. 1990 240, new battery, alternator, battery ground cable. Battery was replaced two weeks ago because it was 7 years old, and didn't seem to hold a charge. New battery was continually dead after a lengthy drive, so the alternator was replaced. I realize I likely only needed brushes/voltage regulator, but since I'd already bought a load of other new parts, I thought I'd splurge. After the new alternator went in, the battery light on the instrument cluster came on...even though though the car was off. Didn't happen with old parts. Light goes off when car is running. Also, even though the car runs fine and can be driven, the battery slowly discharges, and only shows 11.6-ish volts when engine is running. Shiny new alternator, which tested ok at the store I bought it from, isn't charging the battery. I already tried a continuity tester on each of the fuses...nothing. Tried three different alternators, and that battery light won't go out for any of them. I am totally flummoxed by this. Anyone have any ideas???