On the back of your alternator is a regulator with a harness plugged into it. ground the screw that has an arrow pointing to it. sometimes the rebuilt ones or new ones you buy dont work straight from the factory. when you have it grounded ,place a screwdriver at the back of the alt. if it is magnetized your alt. may be working but possibly the reg. isnt. Check out this website called star-alt.com a lot of info there. helped me an awful lot and im a mechanic.
jd
April 2007