First - a very quick question.....
If I run a wire from IGN on the ignition switch, or any LIVE wire for that manner - then connect it to a lamp - then connect the other leg of the lamp to the centre, smaller connection of the alternator should this happen:
key to ACC - lamp comes on
start engine
light goes off after a flick of the revs.
The logic being - 'proper' live to bulb which then earths at the alternator so light comes on - engine starts and sends the same voltage back up the wire - light goes off.
Is that the correct fundamentals ?
For the moment the light comes on but when the engine starts the light goes to 'glow'. It doesn't get brighter or dimmer relative to revs - it simply goes from bright red to a constant dim red. Or am I being dim?
The other question is - the two fat brown cables at the alternator - do they do exactly the same thing? - i.e. provide voltage to the car's electrics. It appears to do that on my car and they go off and do the same job- therefore - why have two cables?
Thanks in advance for any help