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Q: battery won't stay charged.

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I put a new alternator and a new battery. The car starts but slowly dies and the battery hand goes up and down when I use the turn signal

My car has 286000 miles.
My car has an automatic transmission.

Hello. This is a common problem when there is a bad ground connection or a faulty voltage regulator. The bad ground connection will cause the system to fail to complete the circuit which will not allow a full charge. The voltage regulator moderates the charging of the battery by the alternator. When this is not working properly, this will cause the alternator to either overcharge or undercharge the battery. I would recommend having an expert from YourMechanic come to your home to diagnose why your battery won’t hold a charge and repair the voltage regulator if necessary.

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