Alarm and voltage dropped to zero?

[Coop411]

Last night alarm sounded and noticed the starboard engine voltage was zero. Temp, oil pressure all good. Shut down engine and alarm stopped. Started engine a little later (with other battery) and all was fine for awhile with voltage up at 14 volts. Then happened again. The alternator is only 9 months old. Going out to check today. Is it possilble battery was just very low due to charger problem or loose connection? Appreciate any insight. Thanks,

 

[Fastphil]

Could be a few things. It may be a defective alt or shorted internally. Alt belt could be slipping or the battery is not taking a charge. If I was gonna guess, alt failed again. That would be the reason it was at 0 then 14. Internal diodes are switching on n off. Most aftermarket alts like Arco or Sierra have a 12 month wty

 

[Coop411]

Thanks for response. I have been traveling and failed to respond to you. I checked and it was the alternator. Disappointing as it is about 7 months old. Thanks again for response.