I don't know how modern charging system lights are set up, but on older cars the light was on a circuit between the battery and the alternator.
When the key was turned to the ON (but not START or RUN) position, the alternator was not turning and so made no electricity, and therefore there was the battery voltage (typically 12.5 V) on the battery side of the light, and 0 V on the alternator side. This difference caused current to flow through the light bulb, illuminating the light.
When the engine started, the alternator produced about 14 V, and that same voltage appeared at the battery's terminals. With the same voltage at the battery and the alternator, there would be no current flow, and the light would go off.
The light would glow faintly when the alternator output voltage dropped slightly below that of the battery, and brightly if the alternator failed completely.
The fact that the CHARGE (or BATTERY) light is on is a concern.
You need to get hold of a schematic diagram of the charging system, and start troubleshooting from there.
Please let us know how this turns out.
When the key was turned to the ON (but not START or RUN) position, the alternator was not turning and so made no electricity, and therefore there was the battery voltage (typically 12.5 V) on the battery side of the light, and 0 V on the alternator side. This difference caused current to flow through the light bulb, illuminating the light.
When the engine started, the alternator produced about 14 V, and that same voltage appeared at the battery's terminals. With the same voltage at the battery and the alternator, there would be no current flow, and the light would go off.
The light would glow faintly when the alternator output voltage dropped slightly below that of the battery, and brightly if the alternator failed completely.
The fact that the CHARGE (or BATTERY) light is on is a concern.
You need to get hold of a schematic diagram of the charging system, and start troubleshooting from there.
Please let us know how this turns out.
