I have a 2002 Mitsubishi Lancer that has a dead battery every time I turn off the car, but also leave the radio or air conditioner on, or leave any devices on whatsoever. This is weird because the radio is no longer playing and looks exactly like its off, but somehow, even with the car completely off and the keys completely removed, if the A/C or radio switches were left in the on position, then the battery will be dead if I return a few hours later, or overnight.
These devices never used to do this before -- whenever I used to turn the car off and remove the key, these devices would not only go dead also, but they would also cease to draw power and deaden the battery.
Does anyone here have any ideas what might be going on? Im going to show this message to my brother, so if you have any ideas whats going on, he will be able to understand what youre explaining. Thanks.
I would do a full checkup on the charging system.
1. Remove battery, fully charge and load test it. Most parts stores can test your battery or a mechanic should be able to do it for you.
2. With engine running, check voltage, should be at 14 Volts or above. If not, your alternator is not working properly.
3. Check battery drain with an amp meter between the positive terminal of the battery and the positive cable going to the starter. You should be well below .2 amps. If you are above, then I would start pulling fuses from the fuse panel one at a time to see which circuit in the system is causing the drain. From there you will need to then find the offending electrical item (radio, trunk light etc.) on that circuit and fix/replace it.