Oldsmobile/Buick Repair: electrical charging issue, cutlas supreme, chilton manual

Question
86olds cutlas supreme 5.0 4bbl loaded.
after setting for 1hr or more - when re-started the gauge only show it charging about 6-8 volts. 1 to 3 minutes later it starts charging near 13. it takes longer to "catch" if the lights wipers or other "load is placed on the system have replace the alternator with no effect battery is near new and very strong.
There is another issue -- have any ideas?  

Answer
Hi Stew,
If that car has an alt light in the instrument cluster, make sure the bulb isn't burnt out? The bulb indicates low charge, but it also sends initial exciter voltage to the alternator.
With the engine off, and the ignition on, the light should illuminate.
That's old enough that I don't remember where that exciter voltage comes from if there is no light, but it comes through one of those wires in the plastic plug on the alternator, so unplug that plug, and turn the ignition on, and see if one of them gets some voltage. I don't remember which one.
An old Motors or Chilton manual should show it.

Van