Alternator warning light....

[fergus]

Being an electrical dunce, given that my car currently doesn't have an alternator warning light on the dash, do I need to connect the small low current lead which is fed from the alternator to anything, or is the single heavy current brown lead straight to the battery sufficient?

[fergus]

OK, I think I need to connect a lead to the D+ connection on the alternator to a bulb (or probably just a small resistor) through to a switched live which will be on when the master switch is on. I don't think a small LED on the dash will draw enough current.

Is this correct? Is it sufficient?

What causes this to go out once the alternator has started producing power? Should I fit a diode to make the current only flow to the alternator from the battery and not from the alternator?