nrew altenator overcharging new battery like the one that was replaced.

2004 TOYOTA TACOMA
47,500 MILES • 2.7L • 4 CYL • 4WD • AUTOMATIC
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CMB31JEX9
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just put new belts and new altenator in 2004 toyota tacoma 2.7L 4 WD. the old altenator was 21 yrs old just replaced with new one. does same thing. overcharges.
Oct 1, 2025 at 2:45 PM
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BLACKOP555
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Overcharged by how much. And what brand alternator?
Oct 1, 2025 at 7:12 PM
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CMB31JEX9
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it was reading on multimeter over 17 volts while running. its a brand new battery. so i disconnected battery from system since the old altenator destroyed the old battery. i am thinking of replacing just the internal voltage regulator with a new one.
Oct 1, 2025 at 8:39 PM
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CMB31JEX9
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chinese aftermarket altenator.
Oct 1, 2025 at 8:41 PM
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STRAILER
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Yep, I would get a Denso unit, also, make sure the battery cable ends are in good shape, the repair ends can be corroded and cause issues. Here is a guide to help test the new alternator.

https://www.2carpros.com/articles/how-to-check-a-car-alternator

Please go over this guide and get back to us.
Oct 7, 2025 at 10:44 AM