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Q: My alternator and battery keep draining

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Just replaced both the alternator and battery and still there a lack of electrical power

My car has 300000 miles.
My car has an automatic transmission.

This may be a sign of a failing voltage regulator. This is a unit that regulates the charging of the battery by the alternator. Often times this will result in the alternator allowing too much power to be delivered to the battery resulting in damaging wires and prematurely sometimes destroying the battery. In other cases it may result in the alternator not supplying enough power to the battery, resulting in undercharging the battery or not charging it at all. In either case, I would recommend having an expert from YourMechanic come to your location to diagnose your vehicle’s charging system.

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