3g alternator overcharging

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Jan 15, 2010 | 08:50 PM

TourqueRise

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Joined: Nov 2008

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From: Sorrento BC, Canada

3g alternator overcharging

I just converted my 91 f250 7.3 diesel to a 130 amp 3g alternator from a 1993 Taurus 3.8. This alternator is charging 14.9 volts with all loads on, and the same with no loads on. The voltage is the same from idle all the way up to 3000 rpms. I rebuilt the alternator with a new regulator, brushes, and bearings to see if it was the regulator, but it charges the exact same voltage. I used the wiring from the Taurus, and hooked everything up properly I think. Is this high for this alternator or is it normal? Thanks.

Jan 15, 2010 | 08:55 PM

johnboggs21

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Joined: Jun 2008

Posts: 2,500

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From: Michigan

14.9 sounds right to me, but what do i know lol. It has to be more than battery voltage which is 12.6 or it wouldn't charge them, so it sounds fine to me.

Jan 15, 2010 | 09:04 PM

kenpobuck

Cargo Master

Joined: Mar 2006

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From: Sand GAp, KY

That is what my 86 alt charges at any thing above idle. I don't think it is to high as I have never had anything blow or get hot.

Jan 16, 2010 | 12:07 AM

LCAM-01XA

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Joined: Apr 2008

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same here, I usually run at 14.6V at anything over high idle.

Jan 16, 2010 | 09:40 AM

timothyr

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Joined: Aug 2009

Posts: 375

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From: Phoenix

from lots of experience with automotive electrical 14.4~15 is good...above 15.2 keep an eye on things.
Honestly in my mind if you are getting 14.9 full load at idle, and things stay the same at 1500rpm no load I would be very happy....that says on the cold snowy night you wont run out of power while waiting for the wreck to be cleared up the road.