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Old Feb 9, 2020 | 09:31 AM
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If my gen light stays on very dim at idle and then if I use window switch or turn signal or anything else the light gets bright. Is that a ground problem or a short. Body grounded good but gauges flicker erratic like the light. I have schematics just looking for a starting place. Thanks
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Old Feb 9, 2020 | 10:40 AM
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Gen light on generally means the battery is putting out more voltage than the Alt.
Check that the sense wire (two plug wire back of Alt) is plugged in.
If the plug isn't an issue then I'd have the Alt checked.
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Old Feb 9, 2020 | 10:47 AM
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The regulator is dying.
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Old Feb 9, 2020 | 10:56 AM
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Check out put with fluke meter. Also check voltage at idle at battery should be 13 volts plus. Also with car off battery should be 12,25- 12.50 volts Have that alternator rebuilt local;y if it is original to the car these discount auto stores it is hit or miss on there rebuilds!
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Old Feb 9, 2020 | 04:25 PM
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Continuity between the brown wire at the alternator and where it goes into the gauge cluster. 12.5 V at both the battery and the alternator. Less than that at idle. Can anyone tell me if the gauge needle stays horizontal before the key is turn on. Mine doesn’t move without power on
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Old Feb 9, 2020 | 05:36 PM
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Steve, you need an alternator. The GEN light comes on when you turn the ignition on, then goes out, completely, as soon as the motor starts. Don't drive it far like that, the ignition system will discharge the battery.
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Old Feb 9, 2020 | 08:43 PM
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Originally Posted by Steve Kistler
Continuity between the brown wire at the alternator and where it goes into the gauge cluster. 12.5 V at both the battery and the alternator. Less than that at idle. Can anyone tell me if the gauge needle stays horizontal before the key is turn on. Mine doesn’t move without power on
Could be a loose alt belt but more likely a weak/bad Alt. Should be putting out @14v.
12.5 is coming from your battery and "less than that at idle" is your battery struggling to keep up.

Last edited by Hammerhead Fred; Feb 9, 2020 at 08:44 PM.
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Old Feb 10, 2020 | 03:30 PM
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I would like to thank everyone who suggested that it was a bad alternator because in fact it was. So once again thank all of you for your advice and input which I followed and I’m now a semi-happy camper.
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Old Feb 10, 2020 | 06:47 PM
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Originally Posted by Steve Kistler
I would like to thank everyone who suggested that it was a bad alternator because in fact it was. So once again thank all of you for your advice and input which I followed and I’m now a semi-happy camper.
We appreciate you coming back and following up with the root cause.
Makes the search feature a valuable source of info to others.
Too often a post ends without OP follow-up.
THANKS!
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Old Feb 14, 2020 | 04:42 PM
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Originally Posted by Steve Kistler
I would like to thank everyone who suggested that it was a bad alternator because in fact it was. So once again thank all of you for your advice and input which I followed and I’m now a semi-happy camper.
De Nada amigo.
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