hello, im in the process of gettiny my car running, and i do n ot have my alternator hooked up. I do not know if the alt needs a power signal or ground signal to turn on. i have this diagram, i know its the blue wire, i just need to know if i need to wire the relay as a ground or a power.

 

You need to give the Black/yellow switch 12v power. The signal coing from the ECU is not needed or the warning lamp.

 

ony of my outputs is a alternator, should i wire in a realy to give the alternator its needed 12v switched source