16v setup charging issues

[slam 0]

I have an ea alternator with an external voltage regulator. 12v under the hood and 16v 8400 in the rear. When i turn the vehicle on and adjust the regulator charge at 14.4 volts under the hood, the rear is charging at 21+volts. so, ill adjust the rear batt to charge at 18-19v and the 12v batt under the hood is charging at 12.4. Why?

Could this be because the batcap 8400 hasnt been charged in several month and the 12v battery under the hood is at proper charge

btw i do have a system setup to run a 12v and 16v....like a step down

does this makes sense? lol

[dbjunior 0]

how do you have them separated. do you have a voltage stepdown on the alt.

[jonbearsmt 919]

says he dose

[slam 0]

how do you have them separated. do you have a voltage stepdown on the alt.

it does the same as a step down.

[dbjunior 0]

not a voltage regulator but a voltage stepdown like the powermaster pn993 it can step down 2.4 or 3.6v you set your alt voltage to 17v and connect this to the output then the 12v battery to the 3.6v stepdown so it charges at 14.4v there will also be a wire going directly from the alt to the 16v bat to charge it at 17v.

[slam 0]

not a voltage regulator but a voltage stepdown like the powermaster pn993 it can step down 2.4 or 3.6v you set your alt voltage to 17v and connect this to the output then the 12v battery to the 3.6v stepdown so it charges at 14.4v there will also be a wire going directly from the alt to the 16v bat to charge it at 17v.

i sent u a pm

[slam 0]

found something that i thought would fix it.... its better but not completely fix

at idle 500-600rpm

front battery

batcap 8400

at 1500rpm

front battery 14.4

batcap 8400 20.4

now if it was a pulley problem and i fix it, the batcap 16v would also see the difff and wouldnt fix the problem. it would make it worse

Edited November 1, 2008 by money_inc

[slam 0]

does the pos side of the external voltage regulator need to be 16v or 12v? its on the 12v now cause thats b4 i installed the 8400. i think it does, might be be the prob. nebody verify?

Edited November 1, 2008 by money_inc

[slam 0]

switching the pos on the regulator to 16v worked. but im still having issues with the battery under the hood charging at 12.4-12.6 at idle and its at 13.4 at 1500rpm

[WhiteFiver 0]

switching the pos on the regulator to 16v worked. but im still having issues with the battery under the hood charging at 12.4-12.6 at idle and its at 13.4 at 1500rpm

Not many alternators out there (especially for what looks like a fullsize chevy), put out full voltage at idle. It's very common for the voltage to be reduced while at idle; most alternators put out the most voltage above 1000rpm.

Maybe I'm confusing this with amps though...not sure, it's late.

[slam 0]

switching the pos on the regulator to 16v worked. but im still having issues with the battery under the hood charging at 12.4-12.6 at idle and its at 13.4 at 1500rpm

Not many alternators out there (especially for what looks like a fullsize chevy), put out full voltage at idle. It's very common for the voltage to be reduced while at idle; most alternators put out the most voltage above 1000rpm.

Maybe I'm confusing this with amps though...not sure, it's late.

no u are right but.... why is the the 16v battery charging at 18v while the front is at 12v all at idle and all on the same alty

[emperorjj1 2]

huh had the exact same issues with my ohio gen it needed to see itself for the voltage regulator to work properly... but the voltage is the same at any rpm.

hey what amps are you planning on using running at 19v?

[slam 0]

huh had the exact same issues with my ohio gen it needed to see itself for the voltage regulator to work properly... but the voltage is the same at any rpm.

hey what amps are you planning on using running at 19v?

yea thats how i fixed that issue now i need to fix the other

couple of 40.1

Edited November 2, 2008 by money_inc

[emperorjj1 2]

let me know how that goes... a 40.1 would be sweet

[slam 0]

let me know how that goes... a 40.1 would be sweet

and 2 would be better

[emperorjj1 2]

lol ya you got me thinking and i was just reading the new 20.1 thread where u stated you have 2. but i was talking about me. Im having a hell of a time geting an amp to run at 18.8-19v

Edited November 2, 2008 by EmperorJJ1

[slam 0]

lol ya you got me thinking and i was just reading the new 20.1 thread where u stated you have 2. but i was talking about me. Im having a hell of a time geting an amp to run at 18.8-19v

what amp r u running

[emperorjj1 2]

sundown 3000d last thing im going to do is run a ground from the alt to the batteries in the back and see if that helps otherwise look for a different amp

[slam 0]

sundown 3000d last thing im going to do is run a ground from the alt to the batteries in the back and see if that helps otherwise look for a different amp

i wouldnt go over 18v.