1Fine39,

I will attempt to confuse you. The large red wire attaches to the BATT lug and powers the battery and entire system through your ammeter. It will attach to the - side with all (most) of the electrical loads.

The little plug is referred to as the DA plug. The alternator case should be embossed with a #1 and a #2. Your small red wire would attached to terminal #1 and would go to a key switched position that is always hot when the truck is running.

The #2 terminal (don't know what color on your rig) can wrap around and tie in with the big BATT lug. This is the voltage sense wire for the internal regulator.

The alternator case has a bolt or screw on it for a auxiliary ground wire. Is this one of the wires in question. It isn't always used.

The wire from #2 CAN be attached somewhere else...anywhere that it can 'see' system voltage. If you have a horn relay, it could be attached at the BATT terminal there...anywhere it can sense voltage.

I sure hope this helps a bit.

Stuart