can someone tell me how to wire up an A15 internally regulated alternator? I know the big terminal feeds current into the battery but how about the other two wires? I've been told you need a light in the circuit to make it work?
Any help would be cool, cheers.

This was just discussed 4-5 days ago ... see Bosch Alternator wiring?

thanks and sorry dd, can't believe I missed that when it was so recent...

My alternator looks like the second from the right, no. 3.

When you say the field wire goes to the ign, does you mean I put 12v into the alternator? My car only has the wiring that I have put in it (very basic).

nzdatman, DD is right with the 12v onto the alternator field. Youre alternator will not be able to create ANY power without 12v being there. Ive also done an alternator swap and have found replacing the stock 1200 alternator to battery lead with a higher guage wire gives ~ .5volt more available power when the alternator is spinning. Also the other, 3rd wire is prolly a ground. hope that helps!

Quote:

Don't connect the third wire to ground. That's your idiot light. If I'm correct, that wire has a +12 volts on it. It goes to the idiot light and gets hooked to a +12 volts there. When your alternator stops working, the third wire becomes the ground and the light lights.

If you connect that third wire (+12volts) to ground, you'll let smoke out somewhere.

Hope you read this in time.

Got it in time, thanks. Will have a crack at the alternator wiring tomorrow. I'm going to try running it without the light as dd said, the ammeter should show whether it's charging or not.
I'll let you all know how I get on. (ie where smoke comes from first...)

no joy with the alternator...
didn't hook up light, but put 12v into the other (exciter?) terminal.
nothing happened at first...
then for no apparant reason it seemed to work, the volt meter jumped up to about 14-15V from 12V without the alt connected. But strangely, the ammeter didn't even flicker.
Then as I was about to make the wiring permanent, the alternator stopped working, again for no apparant reason. And wouldn't go again. Maybe I'll try again next weekend, perhaps witht the light in the circuit.
I don't really know what's going on...

OK NZdatman can you look on your alternator and tell me what letters are next to the plug on the back, the letters will be positioned next to the terminal of which it is refering. If there are no letters, check if there is a sticker on the side of the alternator with a picture of the plug and the letters on this.

Now DDgonzal we need to make some changes to the info a few things incorrect. One being neither N or S are the warning lamp.
N = neutral point,
S = Battery (+) sensor warning. basically a battery reference to the regulator so it know how to control the alt's rate of charging.
G or L = charge/ warning lamp. This is actually the exciter circuit.
DD I will send you a pm when i get a chance to let you know what else.

Cheers Steve

My alternator is quite a modern looking one made by mitsubishi.
There are three terminals, one stud and nut, with the letter 'B' next to it, I assumed 'battery', the main current output connection. Then at the top (on the back still) there are two spade terminals, at right angles ti each other, obviosly where a plug plugs in, one has an 'L' next to it, I assumed 'light' the other has no marking. I assumed that the unmarked terminal was for the exciter, so put 12V in there. Didn't connect 'L' terminal.
There is no obvious earthm I assumed it earthed through the mounting to the engine block.

Ok cool so its a Mitsubishi
Mitsubishi alternators with the twin pin plug configuration as you describe usually have letters L and R.
L = charge/ warning lamp
R = Ignition 12v +
Now tell me, when you look at the plug and it looks like the shape of a letter T. Is L refering to the vertical part of the T. ( hope you understand)

Now back to what you said earlier,
Quote:
What do you mean "from 12V without the alt connected" ?