I’m a newbie – just bought my first classic car two weeks ago – a 69 Chevelle Malibu 350 with 44,000 original miles. Everything under the hood seems original, including the alternator and voltage regulator. The car has been flawless with the exception of my dash and interior lights going bright/dim/bright/dim, especially when I turn on the flashers. Someone suggested changing the voltage regulator, which I did tonight. The unit I purchased from Pep Boys looked exactly like the original Delco Remy, with the exception the back. Forgive my ignorance concerning technical terms, but the back of the original had two things that looked like screws without heads running between two connectors; the one from Pep Boys had only one. I tried it anyway. When I cranked the car, everything was fine until I backed out of the driveway. At that point, the lights went dim and the generator light came on. Then, the generator light went off and everything returned to normal. A few seconds later, the voltage regulator started buzzing and the generator light came back on. After about ten seconds, the voltage regulator stopped buzzing and the generator light turned off again. I’m wondering if I should put the original voltage regulator back on and change the alternator - maybe the diodes are going bad? Any suggestions? Thanks in advance.