Hi,

I have a 2 pin altenator.

One pin I know goes to a switched live.
The other one goes to a light.
The query I have is does the wire that goes to the charge light then go to earth. The diagram I have seen at
http://westfield-world.com/daihatsu_alternator.html

doe not make it entirely clear where the wire that goes from the charge light goes to.

If someomne could elaborate I would be very grateful.

Cheers

Frank

Normally it goes

Power>light>alternator
At this point with the alt not turning/charging then it is to all intents and purposes earthed and the light comes on.

When the alternator starts charging the earth becomes positive and put's the light out ( as it is not getting an earth.
that's it in simple terms really.

[Edited on 29/12/09 by omega 24 v6]

Hi the large terminal is supplyed direct from the starter motor the dash light is a positve supply from the ignition and gets an earth from the terminal on the alternater i hope this helps

the charge lamp goes to pin 1 of alternator as shown; other end goes to switched live.

in the diagram berlow think of the "fusebox" as switched live.

or in effect goes to the same point as the other wire that goes to pin 2.

if you connect the lamp between pin 1 and battery (as what happens when igntion is live) you will discharge the battery hence why it is switched.

Note: you say 2 pin - but there should be a third terminal or more likley screw post - this goes to the battery (supplies large charging current) but usually is wired to stater motor solenoid.



[Edited on 29/12/09 by 02GF74]

Sorry to hijack briefly..
Can the charge light be any old 12v light or does it need to be a special one in some way (diodes or something attactched)?
Its the last thing to wire on my saab engine and I've been ignoring it till this reminded me i

lamp serves 2 functions:
1. supplies visual indicator that alternator is charging
2. supplies current to the alternator field coils before it "self-excites"

so for 2. the lamp must be of sufficiuent wattage for that, typically 3 W.

which equates to a current of 0.25 A.

why the long widndd answer? basically so that is you wanted to use a LED lamp(like wot I and many other are using), which typically draw 0.02 A, then you need to have a resistor in parallel to draw the right amount of current.