My battery keeps draining down. I did the test ie... remove the ground and put a test light between it and the battery post. At first the light was not lit and everything was good. I wanted to be sure the test was working, so I turned on the parking lights, the light came on and went off when I turned them off. So it worked. I then turned on the ignition switch, the light came on. Turned it off and the test light stayed on. But if I turned anything else on and back off the light would go out. What is going on... It ddoesn't matter what I turn on and off the same thing happens. The test light does not go off when the ignition switch is turned off unless after it is turned off, I turn something on and then off again.

it is a 66 convertible HEI, separate voltage reg,

Have you added any relays to your car? If so, you might unplug them and try. One could be sticking.

Due to other recent issues I replaced the alternator and the voltage regulator.