I just worked on a customer's m-TDI Westy again tonight (the yellow
machine on my website) and last thing on the agenda was battery issues:
BOTH batteries, starting and auxiliary, were almost dead. Checked the
alternator output, 14.2. Batteries were receiving 13.2~13.4. Then I
noticed he still had just the original 8 or 10-gauge charge wire from
the alternator to the starter. So, I clipped that puny wire out of the
circuit and replaced it with a 4-gauge cable, problem solved, now
getting 14.0 at the batteries.

mark drillock wrote:
> After I added the new wire from the alternator to the battery
> compartment I now get 14 volts at the aux battery after driving a while.
> You may want to consider a similar wiring enhancement.
>
> I did not include every detail in my original post, in an effort to keep
> it out of book form. Before I added the wire I saw 14.2 at the
> alternator but only 13 or so at the batteries even after a few hours of
> driving. That was how I knew there was a wiring issue that I needed to
> address.