Diagnosing high voltage

hotrod swinger said

Found this on b-bodies:

step 1. unhook both small spade terminals to alternator and start car, it should not charge at all. if it does its a bad alternator.
step 2 hook up the small 12v wire to the bat spade terminal on alternator but leave the green wire off the field terminal, if it charges at all its a bad alternator.
step3 hook up all 3 wires on alternator, unplug triangle plug on voltage regulator, if it charges than the green wire from alternator to regulator is shorted to ground.

Click to expand...

Here's the thing. "Screwing around" can change the problem. EITHER brush can be grounded, you have a 50-50 chance. If the one connected to the blue is shorted, OR YOU reverse the field wires, you WILL BURN DOWN THE ignition harness

As others pointed out, test either or both brush holders with a continuity lamp or meter to ground. Both should be open. The problem can be right in the rotor (burned windings / shorted to ground) or in the brush holders, either one of them