HELP! charging system BLUES

Sounds normal for a Mopar- Idle speed does have a direct bearing on the amount of voltage to the system. Usually a smaller pully on the alt helps, up the idle speed a bit.

the old alt's only put out power starting around 1200 RPM's below that it can't put out a charge. some of the later alt's- smaller ones off 90's with arounds 75-90 amps with the smaller pully work well- but with 90 amps you better beef up the main power wiring and connectors!!!!!