Alternator Problem

I recently installed 3 autozone rebuilt alternators and 1 new alternator after a 5 year stint of no charging system issues. All of these have been within the past 3 months and to begin with, I was
under the impression it may just be bum rebuilds. Twice in the past couple of weeks I've gone on the road for the weekend where everything looked fine until Monday morning and then, no charge (as per my gauge and verified by a voltmeter). Battery started and ran the vehicle okay (bat is one year old) but no charging system. This vehicle is a 97 GMC suburban k1500, BTW.
This past Sunday morning, I experienced the same thing and shut the car off. This time, I decided to remove the negative cable for about 5 minutes and reconnected. Voila, the charging system worked. It's as if some sort of charge is being held (or accumulated over a few days) or some sort of capacitive action is taking place somehow.
I decided to try the neg cable because the last time I took it to autozone, the alternator checked out okay on their machine (but off the vehicle).
Anyone run into a problem like this in the past? Where a good alternator/regulator seems to build up some sort of charge and won't operate properly? TIA
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On Mon, 12 Oct 2009 20:55:09 -0700 (PDT), snipped-for-privacy@lycos.com wrote:

Have you considered the possibility you may just have a bad ground?
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I was having a problem like this on a 91 SUB (350ci) I had the light for the alternator come on and replaced it. After about one month it would show the volts jumping around on the in dash meter. retest it and the alternator showed fine. The one day it would not start. Hauled it to the chevy place and they found a bad "fuel relay". This has been about one month and every thing is fine. So you might have a grounding issue some where. At least that what the chevy place told me as to why the relay stopped the voltmeter from moving.

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Excellent suggestion, and also check to make sure the alternator activate line is not hot all the time...
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On Tue, 13 Oct 2009 09:07:44 -0400, "Stormin Mormon"

What we need is fewer religion trolls posing as regular users.
Maybe people could be more tollerant about you if you offered a meaningful bit of advice, insetad of making stupid comments.
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On Tue, 13 Oct 2009 15:42:59 -0400, "Stormin Mormon"

I know a troll when I see one.
I also know that religion doesn't belong here.
I respect that is your signature however, but as to going to a cult to learn something... I don't think so.
How about a serious answer for the OP?
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Drive to the nearest LDS church to be taught. Learn more about Jesus. www.ldspam.org
Christopher A. Young (Stormin Mormon) _______________________________________________________________
=== Are you a descendant of the original winking === polygamist, Brigham (I don't care how you === Brigham as long as you Brigham) Young? You don't have a bad alternator, because you get no charging improvement by substituting good alternators.
It's probably not a bad connection at the power wire from the alternator to the battery because you refreshed that connection each time you replaced the alternator.
It's probably not a bad connection at the alternator field input connector because you refreshed that connection each time you replaced the alternator.
Most likely suspects:
1.) Broken wire inside the field input cable, usually right next to or inside the connector.
2.) Bad connection/broken wire/defective relay at the other end of the field cable.
Good luck,
Rodan. .
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Any trouble codes? Is the mounting surface between the alt and the engine clean w/no paint? Also checking all grounds is a great idea, maybe even do a voltage drop between alt output and the battery... HTH, Ben
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Replace the Plus side cable or connector on the battery. When you take the connector off there is a Lead washer in there , replace it. Also check the Neg cable.
Should be CLEAN, I mean Clean. Not kidding. If battery acid got into the cable assembly, the cable is bad.
Cheers
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I had some troubles with the GM OEM cables corroding inside the terminal end. This is not an uncommon problem. You can normally pull back the insulation and take a visual. If they are corroded in this area, I found it better to replace rather than to try to clean and put the old back in service.
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Thanks guys. I'll check into this further with your suggestions in mind. I hadn't really thought about a bad cable or ground because it starts and runs fine even though the alternator isn't charging. One of my next efforts was going to be to run a jumper to the field wire to make sure there's 12 volts on the field the next time it acts up but will also look at all the things brought up here. Appreciate your help.
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