Hello,

I have owned my '84 GL since new.  I live in Phoenix Arizona and all my
battery failures have been typical of the climate: shorted cells.
However, I am now faced with a cool weather problem that I have no
Vanagon experience with.

The symptom is that the engine cranks slowly even after a long drive.
If I charge the battery, the engine cranks just fine for a few days.

So, I looked at the charging system and was reminded again that the
Vanagon uses an alternator that supplies a constant voltage at its
terminals instead of supplying a constant voltage at the battery.  With
the engine at 1000 rpm, I measure 13.8 volts at the alternator with the
lights and heater blowers turned on, but only 12.6 at the battery.  That
is not enough to maintain the battery.

It is most likely that there is a high resistance path in the wiring
between the alternator and the battery.  Bentley shows two parallel
wires from the alternator that connect to a bus wire that runs from the
heavy starter cable to the front of the Vanagon.  I don't know why VW
didn't run those parallel wires directly to the starter cable.  I
suspect the junction of the parallel alternator wires and the bus wire
is bad, but I can't locate the connection.  Can anyone tell me exactly
where it is?

Of course, any other advice on how to trouble shoot the problem would be
appreciated as well.  Searching the archives I saw that some folks have
gone to an external regulator with battery voltage sensing to fix the
low charging voltage problem.  However, my Vanagon has been running as
designed for more than 25 years, so I should probably just fix the
problem instead of trying to improve the design.

Thanks,
Mike