Hi everyone. I have a 1971 Camaro with what I think is a strange problem. My alt /gen light is staying on. I took off the alt and had it tested.The parts store said the alt. was good so I replaced the external voltage reg. The new voltage reg. did not fix the probelm. With the engine off I did a test by removing the negative cable from the battery and used a test light between the cable and the negative battery post. There was no indication of any power draw. The alt. belt is new and tight enough. This is what I think is strange. When the car is running the alt light is on but when I removed the pigtial from the back of the alt. the light shut off. I plugged it back in and it came on again. Does this mean the alt is bad even though the parts store said it was good? I have no idea what the problem is. Any help is appreciated
Thanks
Matt

 

the only true test is a voltmeter. with the engine idling put the red lead to your positive battery post and the black to the negative. it should read about 14 volts and no more than 16. anything less or more and you have problems. sick

 

The parts store man missed it. The alternator was bad.

 

dont ya just love it when that happens, and they keep telling you that , no its good the machine said so
just like when I take my car to the dealer and he tells there is nuthing wrong the computer said so