Mazda 2003 Battery Loses Charge-CAN'T FIND PROBLEM. PLEASE HELP! (Page 1/1) carguy05 FEB 09, 09:40 PM Mazda 2003 battery loses charge but the battery light on the dashboard is off. I have replaced the alternator. I have double checked all the fuses, cables and relays. Have you experienced something similar? Suggestions on what I should do next? seajai FEB 10, 07:07 AM Does the battery go dead as you're driving? Or does it go dead when the car is parked overnight? tesmith66 FEB 10, 07:55 AM Pull the positive battery cable and attach a voltmeter between it and the positive terminal. If there is a drain you will see voltage on the meter. Start pulling fuses until the drain stops- the drain will be somewhere in that circuit. James Bond 007 FEB 10, 10:58 AM Try looking at your car at night, might be something simple like useing the ash tray as a coin box (light stays on when open).Check your trunk light and if you got kids they tend to play with the light switched.Might allso be a bad door pin switch, causeing the courtsey lights to stay on. carguy05 FEB 10, 09:31 PM The car battery dies while driving. carguy05 FEB 10, 09:39 PM Thank you. I checked the car overnight and there is nothing left on. There is no light on or anything of that sort. The battery actually doesn't drain overnight, the battery drains while driving. I measured the voltage and the voltage meter shows that the car isn't charging the battery. However, the battery light on the dashboard disappears. Someone said that it might be the computer or that both alternators are damaged or defective. I took one of the alternators to the auto parts and had it checked, and they said it was good. That's why I don't want to spend money on a third alternator. tesmith66 FEB 11, 08:20 PM Could be a bad battery. Have you had it load tested? GreenPlatypus FEB 15, 05:33 PM What kind of voltage is the alternator putting out while idling and under load, basically all electrical equipment on at a high idle, 1200-1500 rpm? Was it an aftermarket or oem alternator? I have found on a lot of late model cars, they do not like aftermarket "refurb" alternators. And any other lights on like check engine light etc? FriendGregory APR 10, 08:50 PM I am going with a second bad alternator. After the batter is charged, have you left it unplugged and see if it looses voltage by itself? A real volt meter while it is running will tell a lot. Does the alternator have a bunch of loose wires to reconnect after or a big plug? I have seen them miss-wired.