Alternator Indicator

If light remains on when ignition is off, check for shorted alternator positive diode. If light remains off when ignition is on, but the engine is not running, check for burned out indicator bulb, an open light circuit, or, an open in alternator field. If light comes on with engine running above idle RPM, check alternator output, check for a shorted alternator negative diode or loose or broken alternator belt.