Date:         Fri, 20 May 94 08:52:50 PDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Lee Wood"        <Lee.Wood@forsythe.stanford.edu>
Subject:      [A] Need Assistance With Charging System Troubleshooting

Friends,

Before I spend a bunch of money on replacing batteries, alternators,
and black boxes, perhaps some of you would care to advise me on
troubleshooting an electrical/charging system problem:

Vehicle:  '81 VW Vanagon Westphalia (aircooled) - stock
configuration, 95,000 miles (maybe 45,000 on engine - not sure).

Problem:  This problem has developed slowly over the last few
months; it's now bad enough to do warrant attention.  Very slow
cranking speed, ESPECIALLY immediately after shutting engine off
after driving (like after coming to work this morning), and if it
doesn't start on the first three or four revolutions, I need to wait
5 minutes for the battery to revive enough to try again.

Diagnosis so far:  Applying multimeter across the poles of the
resting battery (fully connected in driving configuration) shows
12.4 volts.  Same test with engine at low road speed shows 12.5
volts.  Hydrometer shows consistent battery low-charge state on all
six cells (just into the red zone of the float).  Haynes manual
isn't much help.  Cable connections to battery are clean and tight.
Battery has been kept properly filled with distilled water.  I have
never jump-started the car or charged the battery with a
trickle-charger, so I don't think I've damaged a diode in the
alternator.

Repair efforts so far:  Pulled battery and ensured that ground cable
connection to side of metal battery box is clean, bright and tight.
No help.  Crawled under and disconnected, cleaned (they were a
little corroded) and reconnected all connections to starter (double
checked proper connections).  Small improvement in cranking speed,
but nothing significant or lasting.  Removed and inspected
alternator brushes.  Looked fine.  Haynes said they should be
between 0.4 and 0.2 inches long:  they measured 0.35 inches, so
probably were replaced shortly before I bought the bus 1-1/2 years
ago.

Hypothesis:  (Based on the fact that I  checked all battery physical
parameters, low voltage across the battery with the engine at speed,
and in the 20-minute drive to work this morning I still couldn't get
hardly any cranking speed when I tried to restart immediately after
shutdown...)  Insufficient alternator output and poor battery
charging.

So, friends, what do I do now?  Have I checked all that is practical
to check?  From my efforts listed above, you can deduce my
electrical acumen.  I can do mechanical stuff just fine and solder,
and test stuff with the multimeter, etc.  I just can't diagnose very
well and Haynes isn't much help.  Diagnostic tools are limited to a
multimeter and hydrometer.  I'm well stocked with mechanical tools.
Should I find a shop that can diagnose Bosch electricals and then
confine myself to replacing alternators and batteries and other
recommended black boxes?  I have this weekend, so I'd rather spend
time than money right now, although I will willingly pay for NEEDED
replacements.

Thanks in advance for your interest and assistance.  Please reply by
direct E-mail to hf.rlw@forsythe.stanford.edu.  If I find something
interesting, I'll post the results.

Lee

To:  VINTAGVW@CC.OWU.EDU, VANAGON@LENTI.MED.UMN.EDU