low voltage issue

[greenblaze98]

I just installed my high output alternator and noticed when I im at idle my voltage is 11.5. This is after I charged my optima red top . While driving my voltage is 14.7 buts drops to 11.5. Is this a battery issue or a alternator issue.

please help.

[Guest]

where did you get said high output alternator?

[melonhead]

Did you do the big 3?

[anubis]

faulty regulator or faulty alt all together im guessing

[greenblaze98]

I have a positive wire going from alternator to battery+ and I have a neg. Going from alternator negative to battery negative.

[Rebel4055]

What HO alt do you have.

[greenblaze98]

300 amp I bought

its from a reputable dealer

[EclipseChris]

Alright, i usually don't comment on threads like this but im bored so here goes. When it comes to high output alternators, voltage is not the most important. When you buy a 300a alt, it should put out 300a. Most ho alts are not regulated to 14.4 like we all want.

To test the easy way, check voltage at full tilt. If it drops at all then its bad. If it does not drop then it is providing the amperage that is is designed for.

[dugee81]

Maybe you need a smaller pulley.. 300 amp units IIRC do not have very high output at idle. Then again, 11.5 is seriously low.. For any newly purchased alt.

[Rebel4055]

We sill need to know what HO alt you have to help you further...

It can be a fake Chinese one for all you know.

Edited November 14, 2010 by Rebel4055