Mitsubishi Repair: power problems 95 galant, dashboard lights, bad hope

Question
last night while driving the brake and battery lights came on together and the dashboard lights dimmed, I got home alright so this morning I put a voltmeter on the battery and while it was running on idle it read a little under 12v when I pushed the gas it read about 12.3v so I thought that although this was low it may still charge the battery but then after driving it around the car died and the battery is dead is this a bad alternator or is it that the it might not be turning properly?

Answer
Chris: A fully charged battery should read at 12.6 or higher. If the battery light came on the car and your lights dimmed. When driving around the car died, I would say you need to replace your car's alternator, but also check the drive belt to see if it might be defective or adjusted properly, also check the cables on the battery, but then how old is the battery? Could be the battery will not take a charge but still you should have to check both. There is a way to test the system, the alternator and battery to see which is bad. Hope this helps and God bless: Linda