Alternator Pins (L and S)

[octanepwr]

Hi guys

I am putting a second alternator on my truck in place of the AC pump, the standard one will just be for the vac pump. I have a couple of alternators and both have these L and S pins. Can someone tell me what they stand for?

I guess one is for ground and the other maybe a dash light.

First alternator (Hitachi): L wire is red and white with yellow stripes across it, S is black and white

Second alternator (Misubishi): L is black and white , S is green and white. The second mitsubishi plug I have, L is blue and S is red and thicker than the others (no where near as thick as the +ve though)

Judging by that second mitsi plug and the fact that the S wire is thicker makes me thing that might be ground, and the other is the dash light?

EDIT - Ok I read that L is the dash light and S is 'Sense' which should be battery positive? Someone to confirm please
Also since there appears to be no earth terminal is the earth just connected to the casing and therefore when its screwed into position the casing is earthed?


Thanks

[slide]

One will be to the light, one will be to permanent power. Also will be the B+ main power wire as a third.
I'm just not sure which is L and which is S..

[octanepwr]

Yeah it seems L is the light, S is the sense voltage (i.e battery +ve), then there is the fat cable which transfers the power.

Is the casing of the alternator earthed by the fact it is screwed to the engine which is connected to the negative terminal? I only ask because there seems to be no terminal for an earth so just want to check.

Thanks

[chrome]

i always thought it was L = lamp and S = sense
i had a book around here but skiddys got it

[sibainmud]

You are all right to some degree. L is for light, (switched positive thought incandescent bulb) with a potential of about 7 to 3 volts.
S is for sense (constant or switched and is used to regulate out put voltage)
Common negative ground earth itself through the casing.
Output is the heavy one.
Ignore colours on wires.
Hope this helps.
Cheers,