alternator tests good,but no charge

I replaced the /6 in my '72 Duster with a 360 and now I can't get any charge from the alternator.I even tried a second alternator and nothing, So I took both to an electrical shop and they both tested good. I know I am hooking it up right but it doesn't show a charge at the gauge or at the battery with a meter. Is there something in the harness that would keep it from charging?
Author: admin