Alternator Charging Problem

Hi all
Was wondering what can be wrong with my car. My Alternator charges fully & then it drops drastically almost to 0. Sometimes I'll have to boost the car
to get it going. I've had the battery disconnected for 3 days & it held it's charge pretty fully so I'm thinking that it's not the battery
Any help is appreciated..
Thanks Dan.
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Dan wrote:

Here's some advice, Dan. Identify your vehicle for us. Make, model, year. Maybe engine. Maybe how much mileage on it. It allows other readers a firmer basis to understand the problem.
---Bob Gross---
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Very true,,
94 Grand-Am GT 3100 150,000 miles all equipped-A/C etc

&
car
it's
Maybe
basis to

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Brushes worn out or hanging up because of their reduced length, buy an exchange or a rebuild kit. Stuuder
Black Bomb wrote:

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Also check to see the heavy battery wire on the alternator stud has not burned off inside the crimp terminal and is making intermittent contact. The wire corrodes over time and as the strands deteriorate the amperage load eventually burns off the remaining good ones. Just give it a tug. If it pulls off then it was shot. Cut and restrip the wire and attach a new good quality lug. Disconnect the battery cable of course before you do all this.
-- Mike.................................................... "Opportunities are spawned from crisis"

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car
it's
Hi Dan anytime time an alt. has o charge it is no good. The nominal output for American alt. is from 13.5 to 14.5 volts . Have someone do an output test on it using a good AVR that will eliminate any guessing.
Jim.J
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Black Bomb wrote:

What drops to 0? The battery voltage or charge current? What does the voltage read when the car is running?
I've had the battery disconnected for 3 days & it held it's

How are you measuring the charge? Voltmeter or Hydrometer?
Have you used a meter to see if you have a heavy current drain when the car is not running?
If that is the charge current dropping to zero you have an alternator problem.
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