Date:         Thu, 24 Mar 2011 12:31:26 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Alternator question
Comments: To: Greg Potts <greg@POTTSFAMILY.CA>
In-Reply-To:  <4D8B6B9F.5060407@pottsfamily.ca>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 12:04 PM 3/24/2011, Greg Potts wrote:
>Hi Volks,
>
>There are two issues I have noticed recently with my 87 Wolfsburg...
>
>firstly, the alternator belt has been shrieking like a banshee; mostly
>at start-up, but occasionally I have noticed it at stoplights or when
>revving slightly as I am pulling away from the curb. The belt tension is
>good and the belt seems to be in good shape.

How many millimeters (or tenths of an inch) can you depress it with
your thumb?  If you can press it more than six tenths of an inch
(used belt more than 1 meter long), it's too loose.  And the max
deflection jumps from 5 mm to 15 mm (used belt) at one meter length,
and our belts are only a bit over a meter long...

>  Over the weekend I swapped
>the alternator with a good condition slightly used unit this week I am
>seeing the same results.

Which is what leads me to the above question.

>The other thing I have noticed is that the alternator is not charging
>until I throttle the engine up to around 2500 rpms. It sits at 12V after
>I start the engine and doesn't rise to 14V until I blip the throttle.
>Once it comes up to 14 it stays there until the engine is shut off
>again, with minor drops depending on load.

Having to blip the throttle to get the alternator going is documented
normal behavior, you should find it in your owners manual.  My '84
always did it; my '89 doesn't.  2500 rpm sounds awfully high to get
it started though.  I'd expect more like 1700-1800.

Yrs,
d