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Discussion Starter #1
So I recently installed a 3g alternator and it was working great for a day or two. Then I was getting on the freeway, lost traction and pedaled it through 2nd and 3rd. Immediately after that, the gauge started bouncing around very erratically. It seemed to get better after a few miles of steady driving, but it was still bouncing around a little. I then saw two ZL1's and couldn't resist doing a rolling burnout at about 30mph in 2nd. After that it stopped working all together.

I haven't even thrown a voltage meter on it, but the battery would barely start the car when I got home so I know it's not charging. I noticed the amp light was flickering on and off while the gauge was bouncing, and now the light doesn't come on at all (even when I cycle the key).

What would cause by brand new 3g alternator to stop working?
 

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What car?

You have no amp light during the bulb check?

You will have NO CHARGE, without a operating bulb, and you cannot use a LED.
 

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Discussion Starter #3
I have an 89 fox. I know that the light has to work in order for the car to charge, however I'm curious what caused the erratic gauge movement prior to the light failure.

I'm concerned an issue with the alternator caused the light to stop working, and the system to stop charging.
 

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alt does not affect bulb

if the bulb is burnt out, change it and recheck
 

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Discussion Starter #5
Well I put my old alternator in, and as i suspected everything worked fine, including the light. The issue is with my newer 3g alternator.

Can anyone tell what would have caused the erratic charging prior to the failure? Like I mentioned above, it seemed to be caused by high rpm.
 

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Well I put my old alternator in, and as i suspected everything worked fine, including the light. The issue is with my newer 3g alternator.

Can anyone tell what would have caused the erratic charging prior to the failure? Like I mentioned above, it seemed to be caused by high rpm.
the high rpm killed it, same thing happened to me.
 

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you can put it on a scope and see how the bridge is, or the diodes within
 
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