Electrical system conked out and car shut off while driving! I recently replaced the battery (left interior light on over weekend, battery died. Only use car for around-town short trips, so never time to fully recharge). Battery was at least 8 years old, anyway.

Last night car died while driving. Interior lights and display had been dimming for a day or so, but this took about 30 seconds to completely die. I was able to jump-start the car, but as soon as I turned the headlights on, the car died.

Could this be the alternator, event though the guy at the parts store said the alternator was fine when he replaced the battery? There was pleanty of fuel on board.