charging question

tuff_puff · Post by **tuff_puff** » Sun May 13, 2007 12:29 pm

Do I have to have a dummy light for my alternator to charge? i never ran one with my generator and it seemed to do ok.

12offroad · Post by **12offroad** » Sun May 13, 2007 1:49 pm

what I found that works is to run a power wire to a vw idiot bulb and then run the ground wire for the bulb to the small terminal on the alternator assuming you are using a newer internally regulated alternator. When the regulator turns on the bulb will go out. I have found that I needed to use a vw bulb and stuck in my own lens to match the others in the dash. The reason for this is because I tried to use a different bulb and the light wouldn't go out. I assume it has to do with the resistance in the bulbs. If you look at a 75 and newer bug wiring diagram it is wired the same way. good luck

Speedy Jim · Post by **Speedy Jim** » Sun May 13, 2007 3:17 pm

Yes, you do need the idiot light.
The reason is that the regulator on these alternators can't "get going"
without some form of external ...ummmm...excitation.

The trickle of current thru the little bulb is just enough to do that.
As soon as the alternator begins to produce power, the trickle is
no longer needed and the regulator gets all it needs from inside the
alternator.

More info on this page of my web site:
http://www.nls.net/mp/volks/htm/elec.htm

Probably much more than you want to know right now:
http://www.1stconnect.com/anozira/SiteT ... rnator.htm

Speedy Jim
http://www.nls.net/mp/volks/

MNAirHead · Post by **MNAirHead** » Mon May 14, 2007 5:41 am

DANG...

Speedy. I can't tell you how much time I put into one of our cars trying to chase back why it wouldn't charge...

Now it makes sense.