Alternator Intermittently Charges the Battery

[Huw Powell]

They may have been "badly" worn - that is, in a way that reduced contact 
area.

There may have been contamination between the brushes and armature.

The springs and flexible leads may have become bound up, or the leads 
were too short or otherwise compromised, reducing contact pressure.

The VR (transistor) itself may have developed an intermittent fault.

Glad you didn't have to replace the alternator!

- Huw

On 4/30/2016 11:10 PM, Christopher Gharibo wrote:
> Changing a 6 month old voltage regulator fixed the problem. The two brushes
> were 1/3 and 1/2 worn.
>
> Why does the alternator stop charging with plenty of brush left?
>
> ------ Original Message ------
> Received: Sat, 30 Apr 2016 08:52:07 PM EDT
> From: "Doyt W.  Echelberger" <doyt at buckeye-express.com>
> To: Christopher Gharibo <cgharibo at usa.net>
> Subject: Re: Alternator Intermittently Charges the Battery
>
>> Replace voltage regulator
>>
>>
>> At 08:19 PM 4/30/2016, you wrote:
>>> Another issue on the '91 CQ: the alternator will stop recharging the
>>> battery intermittently. The voltage will drop from 13 to 10V and the
>>> battery light will come on and the car will run on battery power.
>>> The alternator brushes are almost-new and the belt is tight. The
>>> alternator is about 15 years old. What's the next step? New
>>> alternator? Thank you. CG
>>> _______________________________________________ quattro mailing list
>>> http://www.audifans.com/mailman/listinfo/quattro
>>> http://www.audifans.com/kb/List_information
>>
>
>
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