emu to control the alternator?

[RHD]

I was chatting to someone who mentioned his electrician wired the emu to control the alternator so it didnt need the ALT lite to excite the field, how is that done??

[gregpe]

some alternators required PWM signal some of them on/off depend of load ..
some of need just 12v for excitation doesn't matter if this going via bulb or direct..
And some of have regulator inside ecu and in this case external circuitry required to run alternator so is all depend of alternator..