1969 dart alternator problems

Install a '70 up alternator and ground one of the "field" lugs to the alternator case then hook up the other lug as normal, you will see a significant difference at idle. The problem your experiencing is due to a higher than OEM amperage load due to the added and more modern electronics that have been added, "70 and up alternators have a higher out put than the '69 and older units. David