An alternator that draws power when not turning has a bad diode in it. I would take the alternator off and get it tested. Fix the problem instead of putting a band aid on it (connecting the alternator through the ignition switch).
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
