Date: Sun, 27 Mar 2011 15:36:40 -0400
Reply-To: Greg Potts <greg@POTTSFAMILY.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Greg Potts <greg@POTTSFAMILY.CA>
Subject: Re: Alternator question
In-Reply-To: <4d8e5608.5069e50a.6bb1.4b5f@mx.google.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Hi David,
After all of this it appears I had a bad spare alternator. It looks
brand new but has been sitting on the shelf for a couple years and my
local rebuilder recommends against that. When I ground the blue wire I
get a light on the dash. My ammeter reads about .2A of current when
placed between the blue wire and ground.
I switched back to my original alternator, but it's not charging at all,
even at 4,000 RPM.
I am going to switch back to the newer alternator, at least temporarily,
and see what happens. Stay tuned...
Happy Trails,
Greg Potts
Toronto, Ontario Canada
197x Westfakia "Bob the Tomato"
1987 Wolfsburg Weekender Hardtop (ND Graphics graphics wrap)
1988 Wolfsburg Weekender Hardtop (Colleen's ride)
Engine conversion blog: http://www.pottsfamily.ca/wordpress/
www.pottsfamily.ca
BUSES OF THE CORN - AUGUST 12-14th, 2011
www.busesofthecorn.ca
On 3/26/2011 5:08 PM, David Beierl wrote:
> At 12:44 PM 3/26/2011, Greg Potts wrote:
>> As Dennis suspected, the battery light does not come on when I first
>> turn the key before starting the van. Also possibly related: about a
>> week ago I also lost all my dash illumination. The gauges and coolant
>> warning light still function however; only the battery indicator and
>> dash lights seem to be affected.
>
> The only common point is the fact that both wires go through the
> panel connector.
>
>
>> I have removed and inspected the cluster and everything looks OK; I
>> tried swapping the LED's between the OXS and the battery but no luck.
>
> The LED itself actually carries only a minor part of the "tickler"
> current that starts the alternator going. The rest is carried by a
> resistor in parallel - it's the large one you can see labeled as R3
> on 90.8 fig. 4. When ALT lights were incandescents that drew a
> couple hundred milliamps this wasn't necessary. But in this case the
> LED will carry around 15-20 ma, and the 150 ohm resistor about 80 or so.
>
>
>> I also checked the connection of the blue wire on the back of the
>> alternator and it appears to be clean and well seated.
>
> Pull that wire from the D+ terminal and check the key-on
> voltage. Should be +12 but by the symptoms it will likely be
> zero. If it's zero, follow it back to the panel and find out where
> it goes to +12.
>
> If by chance it *is* +12, stick your milliammeter on it and see how
> much current it will deliver to ground. *Ought* to be in the range
> of 100 ma (and the light should light), but again I'm not expecting
> that it will be. Ground it or connect it back to the alternator and
> again follow it back to see where it turns to +12.* Can you read the
> wiring diagram (97.104 et. seq., tracks 6 and 51) or do you need a
> blow-by-blow?
>
> *if it goes to +12 as soon as you hook it back to D+ that indicates
> an alternator problem, but that seems unlikely since you've swapped
> alternators.
>
> Yrs,
> d
>
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