Alternator wiring

I finally had some free time to change out the alternator today. I ran a second wire to the ignition side of the voltage regulator. Instead of splicing into this wire I just used a connector the slide onto the post and has to 2 prongs that wires can plug into. After I adjusted the belt I started the car. Now the amp meter shows just a little towards the discharge side at idle and when I turn on the head lights or radio or both it now plunges into the discharge side. The engine idle speed doesn't change. Is this something I need to worry about or is the alternator not functioning, it's a used unit that a friend gave me, he bought it new and then decided to change over to the one wire GM style. I did check the wires and they are not getting hot, no smoke or smoldering wires.

Thanks in advance,

Dan in Silicon Valley