Date: Sun, 21 Aug 2011 16:40:42 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Intermittent charge [solved]
In-Reply-To: <BAY161-W18FCEC8899A2472390154BA7280@phx.gbl>
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'Twas bad brushes.
So thar I wuz, getting no charge to the engine battery. Generator lamp
on the dash lit, voltage on the voltmeter dropping. The symptoms were
interesting.
1. The voltage didn't just drop to zero (as indicated by the voltmeter),
but was sagging from 12.6V to 12.3 to 12.0 . . . clearly the battery was
connected to the rest of the car, it just wasn't getting any help from
the alternator.
2. It was intermittent -- sometimes the battery was getting charge,
sometimes not. The intermittency didn't correlate with bounces in the
dirt roads, so I doubted a bad wire connection. I figured (without
Bentley at hand) that the only wire that could give these symptoms was
the one between the alternator and the battery, but that wire was tight
at both ends.
3. When the engine was running on battery, the voltage at the output of
the alternator was battery voltage, not alternator voltage, i.e., I read
12.3, not 13.5 or whatever.
So the fading in and out of the charge light and the lack of voltage at
the alternator output both led me to suspect either a failed voltage
regulator or brushes. But voltage regulators are silicon-based life
forms and if repairing consumer electronics teaches us anything, it's
that when transistors fail, they don't come back. Ever.
But how about them brushes?
FORTUNATELY, I had a spare voltage regulator along. Unfortunately, as
anyone who has tried to remove the voltage regulator while the
alternator is on the (1.9L) engine can tell you, there is little
clearance back there. I asked Mrs Squirrel to bring my little ratcheting
right angle screwdriver with a slotted bit with her when she joined me.
But even for that squatty little screwdriver, there is insufficient room
behind the alternator to get to the lower bolt on the voltage regulator.
But if the alternator is loosened up enough, the belt dropped off, and
the pivot bolt below loosened (but not removed, I could not see a way to
get the pivot bolt's nut back on, could not get my fingers in there) the
alternator flopped enough to let me pull the VR and guess what I found?
The brushes were worn down to less than 1/8th of an inch.
Popped in the new VR with its new brushes and Hey Presto! I had charge
back. Mrs Squirrel thinks I am a genius.
<WORRYWART MODE ON>
How did these brushes get so worn? This is an aftermarket voltage
regulator, one of them adjustable voltage ones. I purchased it in maybe
2005 and it can't have more than 10,000 miles on it. But the brushes are
worn to a nub. Photo here:
<https://picasaweb.google.com/lh/photo/IiR5jcW-0ymSTvUcICn8tBDgB3YXDmdwKaW5NVxuWL4?feat=directlink>
(Picasa is being weird about public/private links right now, I think you
should be able to view this image.)
The one I used to repair the situation was the original one. It has to
have 65,000 miles on it and its brushes were more like 3/8'' to 1/2''
long (no longer in front of me to look at).
So I don't understand how the new brushes got worn down so heavily, so
quickly!
--
Jack "Rocket j Squirrel" Elliott
Bend, Ore.
1984 Westfalia. A poor but proud people.
1971 "Ladybug"-brand utility trailer ca. 1972 from a defunct company in
San Clemente, Calif., now repurposed as The Westrailia.
Sent from my kitchen.
> > Date: Wed, 17 Aug 2011 14:02:42 -0700
> > From: camping.elliott@GMAIL.COM
> > Subject: Intermittent charge
> > To: vanagon@GERRY.VANAGON.COM
> >
> > Hey all, I'm sending this from a primitive campsite in the Deschutes
> Nat'l Forest. The last 3 miles to this location the alternator lamp came
> on and battery voltage (dashmount gauge) dropped. Managed to find a nice
> spot anyway. After engine cooled, started it to check alt output and it
> was working again. Have spare regulator, will swap it in. Anything else
> I might look at? Mrs Squirrel will be joining me tomorrow and could
> bring things if anyone thinks VR might not be the prob.
> >
> > Sent from my smartphone with tiny screen & even tinier keypad.
