Date: Sun, 30 Oct 2011 20:50:29 -0500
Reply-To: John Rodgers <inua@CHARTER.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@CHARTER.NET>
Subject: Re: Alternator Troubleshooting
In-Reply-To: <1B913EE6-0FC3-49B8-AE57-58E241BF255A@gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
When alternator lights start showing in any stage of light-up - after
checking all leads, connections, VOM meter readings, etc, BEFORE
putting in another alternator, I pop the rectifier/brush holder out and
see if the brushes are worn out. Most times that's the problem. Replace
and you are on your way. I keep a spare set in my emergency parts box.
$14-$15 or so beats the heck out of $125 or more for an alternator. If
you have your alternator benched checked at your FLAPS and it shows bad
- DO NOT believe them. Put in the spare rectifier/brush holder with new
brushes - then have them check it. Chances are pretty darn good your
alternator will now check good! It may not check good - but it also
may. Personal experience with my FLAPS.
I do go to the trouble of cleaning up the copper contact surface in the
alternator where the brushes ride with a little piece of worn-out
wet/dry sandpaper by holding the paper against the copper surface and
simply turning the shaft. Doesn't take much. If there are bad ridges and
grooves in the copper - then the alternator probably should be replaced.
You can get away with this once in the life of alternator, but when you
go to do it the second time, it gets really dicey and will probably fail
shortly after the doing of it.
John
John Rodgers
Clayartist and Moldmaker
88'GL VW Bus Driver
Chelsea, AL
Http://www.moldhaus.com
On 10/30/2011 5:30 PM, Gregg Carlen wrote:
> Well, turns out to have been a bad alternator after all.
>
> I found a reference online that said to check for continuity across the two contacts whet the brushes touch. After removing to voltage regulate/contacts, sure enough; no continuity on the contact points. Double checked against the rebuilt one i just got from FLAPs and it showed continuity.
>
> Ran down to the local Army base to borrow their impact wrench and swapped the pulleys.
>
> Installed the remanufactured alternator, started the van and 'presto', the battery light is off.
>
> Voltage between terminals B and D remained about 7V, but the B to housing and D to housing showed 13.4V. Same at the battery connections.
>
> Back in business.
>
> On Oct 30, 2011, at 4:06 PM, Roger Whittaker<rogerwhitt1@GMAIL.COM> wrote:
>
>> Dear light up your life
>>
>> Been my experiance with a variety of vehicles that those symptoms lead
>> to a new alternator if the wires are all I'n place
>> Good luck
>> Regards
>>
>> On Sunday, October 30, 2011, Jim Felder<jim.felder@gmail.com> wrote:
>>> I quickly realized
>>>
>>>> that the pulley’s were different between the alternator in the van and the
>>>> rebuilt one in the box, so no-go for a quick and easy swap since I don’t
>>>> have an air compressor strong enough to power an air-wrench to ‘bump’ the
>>>> retaining nut on the pulleys. Tried holding it with a vice and such, but
>>>> really it’s on there tight.
>>>>
>>> You can hold the alternator body in a vice, gently and padded with
>>> cardboard, and hold the pulley with an oil filter strap wrench while you
>>> put a socket on the nut.
>>>
>>> Jim
>>>
>>>> So, some quick testing with a voltmeter:
>>>>
>>>> Test 1: with the engine running, I put my positive lead on terminal B and
>>>> the negative lead on terminal D. The voltage was 7.1V. Battery light still
>>>> on dash.
>>>>
>>>>
>>>>
>>>> Thinking this is a bad voltage regulator or brushes, I pulled the voltage
>>>> regulator out. A little grimey at the metal contacts, but the brushes
>>>> looked fine. Cleaned the grime off and re-installed the regulator. Restart
>>>> the engine and check voltage across terminals B and D and I get 7.1V.
>>>> Battery light still on dash.
>>>>
>>>>
>>>>
>>>> Just for kicks, I pulled the regulator out again compared it against the
>>>> one in the new alternator from FLAPs and they look identical physically.
>>>>
>>>>
>>>>
>>>> Test 2: Installed the new voltage regulator into my old alternator. Started
>>>> the engine and tested across terminals B and D and I get 6.9V. A few other
>>>> measurements at this point (wish I had taken them in previous tests):
>>>>
>>>> Terminal B to alternator housing: 11.75v, dropping to 11.5v after about 30
>>>> seconds
>>>>
>>>> Terminal D to alternator housing: 4.57v
>>>>
>>>>
>>>>
>>>> So, given that information and testing, I’m thinking either I have a bad
>>>> alternator (diode, perhaps) or I’m chasing down the wrong path altogether.
>>>>
>>>>
>>>>
>>>> One other caveat to mention: on my original alternator, the suppression
>>>> condenser was not mounted the same as the new alternator from FLAPs (which
>>>> was connected to terminal W and the alternator housing). Mine has had the
>>>> connector cut off and mounted to Terminal D, and the condenser itself had
>>>> the hole enlarged and mounted to terminal B. Don’t know that this would
>>>> cause an issue, but thought I’d mention it. It’s been this way since I
>>>> acquired the van earlier this year.
>>>>
>>>>
>>>>
>>>> Any thoughts or advice on other things to check? Or, next steps to take? Do
>>>> I replace the alternator at this point (find a way to swap the pulleys or
>>>> get a replacement one with the correct pulley)?
>>>>
>>>>
>>>>
>>>> Thanks in advance!
>>>>
>>>> Gregg
>>>>
>>>>
>>>>
>>>> 91 Westy (Blueberry)
>>>>
>> --
>> roger w
>> From Proverbs:
>> Under three things the earth trembles, under four it cannot bear up: a
>> servant who becomes king ...
>> ----------------------------------------------------------
>> Explore printed work at: http://www.prliving.ca/
>> View the growing list of video work at:
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>> http://www.prpeak.com/articles/2010/11/29/multimedia/video/doc4c62e5f80d228504902172.txt
>
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