Here's a followup to the story.

I bought a clamp-on AC/DC ammeter that Jeff mentioned.

I found a completely different alternator that I had laying around.

Installed it on the forklift and again, no power produced at idle.

However, we sped up the idle just barely, something like 10% higher,
and now we get nice 4-5 amps charging current at idle.

We also had to figure out which wires were for what. One was for
voltage sensing and another was for jumping the field.

For the original alternator, I purchased a rebuild kit and we rebuilt
it ourselves.

Thanks a lot to all for your help and encouragement.

i