My gen light is lit. Charging system is definitely bad ( while running the engine, I disconnect the positive cable of battery and engine dies). I took my alternator to my local parts store for a free check and it passed. But my alternator is not original. It came with the car (68 Firebird) when I purchased it. The little info I have from the previous owner is that my engine came from a 1970 pontiac. So, when the guy at the parts store asked me for what car, I told him it was a 1970 firebird, just so he can figure out what cable adapters he would use. My questions is, would my alternator pass the test with a 1970 firebird specifications and still not work with my 1968 Firebird? Thanks everyone.