[Peter]

There are basically threee things that must be in place. A working generator, a working voltage regulator and an intact wiring circuit, including the generator light....you need that light to be able to charge the battery. Does the light come on when you turn the key before starting? That at least tells you the bulb is OK. If the generator light is off when the engine runs, next thing you want to do is still measure the voltage at the battery. See if there's a difference whether the engine is running or not. You should have at least around 13.8 volts when the engine runs, it maybe a little above idle. So check your wiring, then your voltage regulator, and exchanging the generator would be last, it's the most expensive part. There are companies that can check your generator for you though.