On Fri, 06 May 2011 08:32:12 -0700, Stephen Trapani
wrote:

Do you have the
Fluke switched to DC amps, and on the correct scale?

Yes. I'll ask the guy who loaned me the Fluke to be sure.

I called Fluke. The setting I used was supposed to give me straight DC
current. So...mystery NOT solved. Where's that damned Larry when you
need him???

Unfortunately Larry has been MIA for a while now.

You could try him he larryw4csc -at- gmail -dot- com

Wilbur is correct that the alternator puts out pulsed DC but the Fluke
should average that out to the correct value. The load of the battery
also acts as a giant capacitor to further smooth the output.

I think at this point you'll need to try temporarily replacing your
other ammeter with a high quality shunt type unit and see what you
get. As I understand it the output of your alternator goes directly
to one side of your ammeter, and from the other side, directly to the
battery?