LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Need help diagnosing alternator issues.

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Old 02-25-2017, 12:41 AM
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Default Need help diagnosing alternator issues.

All right community. I have the Camaro running again after nine years of sitting in the garage. I am having issues getting the battery to charge. All the stock main harnesses have been replaced by using FAST harnesses. See signature for modifications to car. I noticed the car was not charging by looking at battery voltage on my laptop while I was logging data. Battery voltage dropped to 10 volts and the car started running like crap. After having the alternator tested the results came back all good. What I am thinking is that during this time I had not yet hooked up the wire that goes to the dash to monitor battery voltage. Is this also the wire that "excites" the alternator? I removed the battery connection on the back of the alternator to check to see if voltage is coming off the battery post on the alternator and there is ZERO volts, but the red wire that connects to the gauge in the dash was not connected. Is this the issue? Any help would be greatly appreciated. Thank you, Rob.
Old 02-25-2017, 01:38 AM
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Wait, so the exciter wire isn't hooked up at all? Of course your alternator's not going to work like that.

And it's not for the cluster voltmeter, it's for the "Check Gages" light.
Old 02-25-2017, 02:13 AM
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Spartan, so that red wire that feeds the instrument cluster is also the wire that provides the alternator excitement? I more familiar with typical GM 3 wire alternators and nor the one wire alternators. I'll check again in the morning once all the neighbors are awake. Thank you.
Old 02-25-2017, 03:31 AM
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One time I was having charging issues and took the alternator to an auto parts store for testing. They gave it the green light but I replaced it anyway because there was no other explanation for what was going on. The new alternator fixed the problem.
Old 02-25-2017, 07:29 AM
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Originally Posted by ramermanz28
Spartan, so that red wire that feeds the instrument cluster is also the wire that provides the alternator excitement?
Yes. It won't charge without it.
Old 02-25-2017, 11:07 AM
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Originally Posted by ramermanz28
Spartan, so that red wire that feeds the instrument cluster is also the wire that provides the alternator excitement?
Yes, it won't work without it. It doesn't really feed the cluster, it's only for part of the Check Gages indicator. It goes from fused power, through the cluster, right to the alternator.

Courtesy of Shoebox above:
http://shbox.com/1/starter_charging_95.jpg
Old 02-25-2017, 12:53 PM
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You guys are the best! As soon as the neighbors wake up it's time to check it out. I also learned that since this alternator has been sitting for 9 years that when I had the alternator checked it actually re-excited the alternator. I didn't know a self exciting alternator would require that. They lose their magnetism that excites the alternator after long storage. Thank you, Rob.
Old 02-25-2017, 01:22 PM
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Well if the neighbors weren't awake they are now. Everything is working! You guys are the absolute best! Thank you, have a great day. Rob.



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