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Re: voltage variance, '89 100Q

>>  > I bet you have a bad diode in your alternator. It is a
>three phase generator, > that has a full wave rectifier that
>converts it to DC. >  > I'd take it off, bring it to a local
>alternator shop, have them troubleshoot it > and put in a new
>regulator if required. > 

> Ill bet its regulator brushes and/or dirty slip rings. At idle,
>you arent  exciting the field enough for the rectifier. If it
>goes away at rpm,  thats exactly what it is. A bad diode wouldnt
>go away. Bob

But once the alternator came up in speed, the generated voltage from the other
two phases and half of the third phase (considering only one diode is bad), it
would generate a smoother, stronger output. The field could be in saturation at
idle, then once the speed comes up, so does voltage, the field is reduced to
make the output what it should be.

If it was a diode, and the others are the same age as that one, then I wouldn't
doubt that another is going to fail sometime soon. I'm not saying I'm right, but
you should take it out and have it looked at.


Paul Waterloo
HydroAire Incorporated
TEL: (860) 267-7714
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