98 Mazda Protege, something is killing my battery. I was driving around without problems and the next day the battery is dead. I charged the battery and within hours it was dead. Replaced old with new battery. Within days it was dead. I replaced alternator and charged battery. With in hours battery was dead. Does anyone know how to trouble shoot what's killing the battery? Any help is appreciated.

 

Very first thing to do is look for anything remaining on with key off and out of ignition (ie radio, trunk light, dome lights,glove box light, etc ). Anything on is drawing power and draining a battery. Do you have an ammeter or able to get a hold of one? This is the only reliable way to look for electrical draws on the system. First disconnect the negative battery cable and instll a jumper wire between cable end and post. Connect the '+' or red lead to the cable end and '-' or black lead to the battery post. Turn key on but do not crank or start. Now turn key off and simulate exactly what you do when getting out of car normaly. Open door and close. Lock doors if you normally do. Arm any alarms etc. If there is a hood switch for an alarm make sure it is held down also. Look at ammeter reading and then disconnect the jumper wire. The reading should be below 50 miliamps. 50-100 is marginal and above 100 is too much draw. A trunk light being left on will draw around 200miliamps or 200mA. If reading is above this then start removing fuses until draw drops to the normal level of below 50mA. Post with the fuse removed and we can go from there with a wiring diagram.

 

Tks for the info.....I'll get right to checking things out.

 

Post back if you have problems with the tests or need additional info.