1969 Problem with alternator, regulator or both

[VA_Alfa]

I've got a 69 1750 spider with 68,000 miles. Likely has the original Bosch alternator and external voltage regulator. Over the past 300 miles, the Generat light has been glowing brighter; initially just at idle but has progressed to glow very slightly even at 3000-4000 rpm. Now glows as bright as when the key is in the Marcia position and the car is off.

Tonight I cleaned the connections at the alternator, battery, and the regulator but no improvement. At idle, I lifted the positive connection to the battery and the engine quit, indicating the electrics are running on the battery and not the alternator.

Next steps? Should I assume the alternator or regulator or both have failed?


EDIT: Also verified the belt is tight (not slipping) and the voltage at the battery terminals is steady at approximately 12.6 VDC with my analog multimeter with the engine off, idling, or revving.

[ossodiseppia]

Take you car to Autozone or some other auto parts store and have them test the alternator and battery. It's usually free.