i left my headlights on and then my battery light came on... soon after the battery died. i replaced the battery but the light is still on? whats going on... could it be the alternator?

 

how does your headlight stay on even though your car is off? my car when i turn the car off with my headlights on it also turns off with the car.

 

Battery light usually means alternator, that happened to me about a week ago. But before you do anything, take your car to Advance Auto Parts and they have a machine which tells you what is wrong. If it is the alternator, dont bother buying a new one, just take yours out and bring in into a battery/alternator shop to get it rebuilt for ~$140

 

where is the alternator located? today i was driving and the engine and everything just shut off.

 

Your alternator went out man . Im not sure about the SC400's either, youd have to ask someone else or do a search