Side profile picture of the OEM SI 21 Seriers Alternator

This alternator is rated at 13.5 volts, 160 to 190 Amp output current configuration for my application.

The unit has a single external fan configuration. Although it is well within the required power requirements, in this case around 2300 Watts. It has repeatedly failed after about 18 to 24 months, due to a thermal breakdown of the regulator diode assembly.