My battery keeps dying and I don't know why. I first replaced both the battery and alternator. Was fine for a couple of months and then started dying every day again. I turned in my battery for a new one because the fluid level was low. Was fine for a month, started dying again. I've done several parasitic drain tests, nothing comes up. So I had my mechanic friend check out my car, and he took out my alarm wire (which we thought would be draining my battery because my alarm was going off sometimes for no reason) and charged my battery for a little bit, then my car was fine for a month and a half. Now it's still dying and can't really hold a charge for more than a day. I need to fix this problem now before I need to buy another alternator and battery again.
My car has 167000 miles.
My car has an automatic transmission.
There are three possibilities, to start with: 1) there is a voltage drop in the wiring between the alternator and the battery; 2) the "parasitic" power draw occurs while the car is running, not so much while it is off, thus overwhelming the alternator and consequently the battery is not being fully re-charged; 3) there is a parasitic power draw when the car is off but to pick it up requires data logging. With regard to these possibilities, if you desire that the required diagnostic steps be performed by a certified mechanic, please simply request an electrical circuit/charging system diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
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