Alternator regulator

[Atlan]

Originally Posted by MarkS

I would query why you would expect to see an AC voltage across a heavy duty 12V DC battery.

Diode failures may also allow AC current to leak into the electrical system. AC voltage creates electrical “noise” that can confuse electronic modules and digital communications. A leaky diode also can allow current to drain out of the battery through the alternator when the vehicle is not being driven.