[jmt0645]

i got to thinking today () since our alternators are pcm controlled, can the voltage be adjusted within a tune?

[JackandJanet]

Originally Posted by jmt0645

i got to thinking today () since our alternators are pcm controlled, can the voltage be adjusted within a tune?

Are you sure the voltage is PCM controlled? I thought it was just PCM monitored. If it is controlled that way, Bill would have to answer your question. It might be something he could set, but I don't really see an advantage in doing so.

- Jack

[cleatus12r]

I THINK the later 6.0L trucks can but I have seen nothing in the way of gasoline trucks that supports that idea.

[jmt0645]

Originally Posted by JackandJanet

Are you sure the voltage is PCM controlled?.

- Jack

everything i've read suggests the PCM actually supplies the field current for the rotor through the regulator, that the regulator itself is merely a "potentiometer" that is turned by the PCM, thats what got me wondering. the reason i ask is i'd like more charging current for my battery bank for the stereo.

[Longshot270]

The alternator can only work so hard without burning up. You could either run the risk of overcharge or having parts burn up. If your current alternator isn't cutting it then you'll need to go bigger mechanically. If you are having trouble at idle you could try to raise the idle speed. Kinda like I can program my truck to rev all the way to 10K, but the mechanics might not survive.

[JackandJanet]

Originally Posted by jmt0645

everything i've read suggests the PCM actually supplies the field current for the rotor through the regulator, that the regulator itself is merely a "potentiometer" that is turned by the PCM, thats what got me wondering. the reason i ask is i'd like more charging current for my battery bank for the stereo.

Thanks, that makes sense (how it's controlled), but I agree with Longshot here. If your current alternator isn't up to the task, I'd see about a 200 Amp one.

- Jack

[jmt0645]

I already have a 250 amp mechman alt but the PCM limits it to 14 volts. I was only looking to go to about 14.5 volts

[Longshot270]

Is the pulley the same size? My truck will let it go up to mid 14s while driving. Upper 13s while idling.

[JackandJanet]

Originally Posted by jmt0645

I already have a 250 amp mechman alt but the PCM limits it to 14 volts. I was only looking to go to about 14.5 volts

OK, I don't really think 14.5V is a good idea. 14.0V means your battery is fully charged, or you would be reading something lower. I think 14.5 would try to overcharge the battery, and that, of course would hurt it. A 14.0 Volt output also tells me your alternator is fully up to the task.

Finally, your electronics might start to suffer at 14.5 Volts.

To see if your battery is charged, you need to have an Ammeter in series on one of the battery cables. If the Ammeter reads near zero, it means it is not accepting a further charge because it's fully charged. At a resting state, disconnected, and with the surface charge from charging worn off, the battery should show about 12.7 no-load Volts if it's fully charged.

- Jack

[Longshot270]

What are the amps on your battery then? That might be your weak point. If you feel that the stereo isn't hitting hard enough what gauge wire are you using? Also do you have any capacitors wired in?