Dual Alternator - LS1

I'm hoping to find information on "how to" for using two alternators with the '0411 PCM.

Shading thoughts, information, or links will be greatly appreciated.

dave w

Is this for some permanent need or temporary high power consumption? If it were me and temporary, I'd bracket in the second alternator (a 150 amp Escalade "KG3") and then set up switches for the "F" and "L" terminals to remove power from the field windings when I didn't need the extra power. If I let my mind wander here a bit, I'd probably wire in a variable potentiometer to control the output rather than overwork my 0411 PCM with extra voltage control.

Rick

It's for a permanent installation. LS1 powered 69 Oldsmobile Cutlass, with a power hungry Audio System:thumbsup:

dave w

You can wire the alternator using a lamp as a charge indicator and turn off the L and F terminal usage in the calibration. I'd use two separate indication lamps so you know the status of each alternator. Basically feed each indicator lamp with a switched ignition feed. Other sides of each lamp goes to the L terminal on the corresponding alternator. Key on and lamps illuminate. One engine is running, and the alternator is charging, the lamp goes out. If you use LED indicators, you may have to parallel a 500 ohm resistor across each LED indicator to have enough current to excite the alternators. See attached diagram.

It appears the LS1 has a CS130D series alternator. Perhaps the above diagram for the CS130 / CS144 series alternators will also work with the CS130D series alternators?

dave w

if it's truly a monster system, and you're planning a second alternator to power it, the power requirements of the stereo are high enough where you will run the amps from a separate isolated battery bank, right? if that's the case, are you planning any connections between those banks or is it going to be truly isolated? it's really easy to deal with if it's fully isolated.

i have to say i've worked on more than one 'monster' system where people had assumed their ~3000 watts of sub amps were actually going to consume ~3000 continuous watts. they jumped through a lot of hoops and did some major engineering before actually figuring their mean power requirements out, only to have me come by later, and rip the second alternator out of there and redesign the system with half of the parts. class D amps playing music through subs just don't need a lot of mean power so planning the system accordingly allowed us to get by with just installing a slightly upgraded main alternator to keep the deep cycle in the trunk alive (while being properly isolated so you could still drive home after a parking lot party, of course). i had a guy last year with a problem car that would slowly drain the (single) battery when cranking the tunes in hours of stop and go traffic. i just threw a different pulley on the alternator. i didn't even have to change the belt in that one.

of course there are lots of different approaches to big stereos, i had a friend who thinks he's an audiophile running four class AB amps into two DVC subs and real class A amps for his mains for some insane reason (.. the reason is actually dampening force.. but i bet you'd never tell the difference in reality, which is what makes it insane). those things draw more power than an electric furnace before the music even starts playing, and he definitely did need a giant second alternator in that one.

I'm building a LS1 harness for the project, and was asked, "if possible" wire two alternators to be PCM controlled.

I can't go around re-engineering in another shop, union rules. :laugh:

Likely, I will defer the alternator wiring to the union shop. :thumbsup:

The Dyno Tuner is union also, so they are doing the PCM Flash.:mad1:

This might help https://cityofunion.com/

dave w

:popcorn::laugh: Always love Dave W's sense of humor! Sounds like a mess of a project, but totally doable.