Join Date: May 2005
Location: Grand Marais, Minnesota, USA
I use a Geo Metro alternator on my GL1100. It has one lead for the charging, which should be obvious on your alternator.
It also uses only one additional wire to active the exciter, which makes the alternator work. This is a small gauge wire, activated by the ignition switch. On the Geo alternator there are three spade fittings for it to go on. I don't recall which one it is, but a fast test of each spade fitting with the alternator spinning,and a volt meter across the batteryor ammeter in the circuit will tell you when you connected the right lead.
You might need to take your alternator off, and bring it to an automotive electrical shop, or a local garage, and have them test and identify which leads are used for what.