Description & Operation
WARNING: This page is about a different car, the 2004 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
The generator has a built-in regulator with diagnostic functions and voltage regulating functions, such as the following:
- Voltage regulation: The On-Off operation of transistor TR1 connects and disconnects the field current circuit which provides a constant output voltage level. See Fig 1.
- Diagnosis warning is when any of the following problems occur the charge lamp illuminates:
- No voltage generation: Brush wear exceeds specified wear limits, field coil circuit is broken, etc.
- Excessive output: Output voltage is greater than 16 volts (approximately.)
- Terminal B disconnection: Harness is disconnected from alternator terminal B.
- Terminal S disconnection: Harness is disconnected from alternator terminal S. In this case, voltage is slightly greater than specified regulated voltage; however, voltage regulation is still controlled and the battery is prevented from overcharging.