Stereo & Electronics - Alternator signal wire????

I need to know what sends the on power signal to a 96 LT1 alternator. The wire from the alt. plug goes to the guage? When the gauge receives power it sends the signal to the alternator?

How do I hook this up to a switched ignition source? I tried straight twelve volts and the alternator was charging at like 19volts:eek: This is in a swap vehicle and the generator light wire isn't hooked up to anything and apparently does not go to red pin 15 on the pcm like a LS1. I have searched posts and all of my resources for the info. Please help.

That was a hot wire jumped to a switched ignition source that produced 19volts. I just tried hooking the wire coming out of the alternator plug directly to the pos. battery terminal. I only see 12.1-12.2 volts at a high startup idle. Good battery with full charge 12.65v, brand spanking new alternator, but it is displaying the same symptoms as the one that that tested bad. When I first hooked up the new alternator with the signal wire connected to nothing ( thought it went to the pcm) it was reading 11.5v less than the bad alternator so I charged the battery and ended up with what you read above. I am stumped and frustrated. I sure hope some one has a better idea than mine.

I mean it is just two freakin' wires and a good ground, what in the hell am I missing????