Just bought a used 2015 Honda Accord LX. Took it to autozone and tested the alternator and battery. The alternator failed the test so I changed out the alternator to an aftermarket one, it’s still testing bad and after I checked the battery using a multimeter, with the engine running, the voltage stays around 12.8 volts (instead of around 14). The cables don’t seem to be damaged and there’s no corrosion on the battery terminals. So should I change the battery or reinstall the original alternator?
any advice would be greatly appreciated.
Weren't the battery and charging system checked during the pre-purchase inspection? Are there any symptoms? Charge light on? Battery going dead?
You may have a "smart" charging system where the computer-controlled alternator only charges the battery as needed. It's also possible you got a defective alternator. (The quality of aftermarket parts these days is pretty bad overall.)
The voltage is too low for a new alternator. I'd have it bench tested to ensure it's bad. Depending on the car, it should have a certain specification for amps output too.The alternator failed the test so I changed out the alternator to an aftermarket one, it’s still testing bad and after I checked the battery using a multimeter, with the engine running, the voltage stays around 12.8 volts (instead of around 14)
you could have a corroded engine ground strap, or burnt out alternator fusible link. voltage testing should be done right on the alternator positive post and housing.
