[cam808]

Howzit going everyone,
so i just installed my load boss 200 amp alternator today and my idling voltage is abnormally bad, when i was at the stop light i hit 12.5 volts so theres definitely something going on. I have the big 3 upgrade done in all 0 gauge wiring and i am running 2 batteries, one die hard platinum and one Duracell group 31 for my car stereo. When i rev up the RPMs to about a 1000 it holds steady at 14 volts and i have no issues but when i'm at idle sometimes the voltage will drop and my battery light on my truck will come on, any idea on the problem?
do i need a smaller pulley?
is the alt no good?
any suggestions will help!:th_woot:

 

[Rick_crew]

Two batteries?
Both from the same alternator?

 

[hmmbagodden]

A little Google snooping suggests that this is a known issue with that brand, that is at less than about 800rpm the voltage output is crap.

Smaller pulley will likely work. IMO, I would return it and get a better brand...

 

[cdk]

didn't @Supermodulation get one of those and had the pulley swapped for a smaller one?

 

[Supermodulation]

Your idle will have to be slightly bumped up.
Also how did you run your battery negative wire?
Make sure the Big-3 battery (-) is going threw the Battery regulator located just behind the battery. If it doesn't sense a voltage drop it thinks the battery is full no load ie. turning off the alternator.

 

[Rex Kramer]

Make sure your alternator ground is good. Mine was acting up until I ran a cable directly from an alternator bolt back to the battery.

 

[crazyeyez]

yea. when I installed my 150amp ALT, I had to bump the idle up some to compensate.