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GEN Light Help Needed

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Old Oct 14, 2006 | 02:57 PM
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Default GEN Light Help Needed
GEN light is on. 78 with no AC.

Battery read 12.5 off and 14.5 while running. I checked the alternator and it read 14.5 running at idle.

Any ideas of what is causing the GEN light to remain on?

Thank You
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Old Oct 14, 2006 | 05:52 PM
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Check the choke heater fuse,if it opens up it will give a drop out the choke heater relay and the Gen light will get a ground thru the choke heater.
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Old Oct 14, 2006 | 08:21 PM
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Gen. Light ? Where is it,in the tach or speedo? I dont see it in the wiring diagram all I see is the voltmeter.
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Old Oct 14, 2006 | 09:05 PM
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Originally Posted by DWncchs
Gen. Light ? Where is it,in the tach or speedo? I dont see it in the wiring diagram all I see is the voltmeter.
Center console.
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Old Oct 14, 2006 | 09:14 PM
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Oh yea below low fuel light.I couldnt place it and still cant find it in my wiring diagram.
Edit -OK found it---I have a cold
Last edited by ...Roger...; Oct 14, 2006 at 09:21 PM.
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Old Oct 14, 2006 | 09:15 PM
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my gen light did the same thing on my '78....took the alt to advance auto and they tested and said it's ok....finally when I put my stroker in i went with a new alt too....no more light...i think the alt that I had that AA said was good, was actually a POS and the culprit all along.
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Old Oct 14, 2006 | 09:31 PM
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You can pop a diode and turn that light on and still show good voltage.Go to Autozone and have them test it.A diode trio is only about $5
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Old Oct 14, 2006 | 10:39 PM
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thats true you can, eliminate that possibility by disconnecting the connector on the side of the alternator.
There is a post I did in here a while back on how that circuit works
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Old Oct 15, 2006 | 07:57 AM
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Originally Posted by SIXFOOTER
Check the choke heater fuse,if it opens up it will give a drop out the choke heater relay and the Gen light will get a ground thru the choke heater.
Where is the choke heater fuse?
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Old Oct 16, 2006 | 08:08 PM
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Anyone?
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Old Oct 16, 2006 | 10:35 PM
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Default gen light
you probobly have bad diode in the alt. it will feed both ways and make your dash light illuminate. do not replace your alternater if it is origional. have it rebuilt.
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Old Oct 16, 2006 | 11:23 PM
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Choke heater fuse topmost on right. Most likely it is an alternator diode causing the problem, they die and that gived a ground path for the light. Unplug the connector on the alternator, light goes off, there is your problem. If the heater fuse is blown, replace it, see what happens
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