Disconnecting any charging system with the engine running is risky business- - - - -I've seen the signal trace on an oscilloscope spike to over 100 volts just as the connection is broken. Stovebolt electrical systems are pretty primitive and rugged, but trying that on a newer vehicle with an alternator and a few computers can do a huge amount of damage in a split second. There's a whole series of charging system tests somebody who is willing to follow directions to the letter can do, but it all begins with good wiring and clean, tight connections. No shortcuts or SWAG ("Scientific Wild-donkey Guesses") allowed!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!