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Q: Battery is going dead overnight

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4 days ago the battery light came on and then went off. Since then we have been waking up to a dead battery every morning. I put a new battery and alternator. The old alternator did test bad at AutoZone. Do you think it could have been an open diode in the alternator?

A: Hi, thanks for writing in. If the issue has...

Hi, thanks for writing in. If the issue has been resolved by replacing the battery in the alternator it is likely that the previous alternator had a faulty diode. If the issue has not been resolved by the replacement of the battery in the alternator it is possible that the wiring between the two parts has an issue such as damaged insulation burnt wiring or corrosion throughout the wire. If the issue has not been resolved I would recommend having this wire inspected by a qualified professional to determine if it requires replacement. Here at YourMechanic, we can have a technician come to your home or office to inspect your battery issue for you, and make or suggest the necessary repairs.

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