Date:         Sun, 14 Oct 2012 11:04:23 -0400
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:      Overheated wire junction on 1.9
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I want to describe an issue I found while working on my van. Most will
probably not have this problem unless they are running an '83 or '84
digijet (1.9) camper van and draw a lot more out of the alternator than
a stock van does. But if this fits your situation, it bears inspecting
for this potential problem.

I'm in the process of totally revising the charging system because I am
increasing the size of my house battery. The previous house battery
(which I killed by letting it discharge) was a 130 amp-hour deep cycle.
To charge it I used a DC > DC battery charger* set to the high-current
15 amp mode (later versions are limited to 7 amps, but 15 amps
better-suits larger batteries like mine).

The charger pulls about 18 amps from the van's charging system. The
wiring to the charger was less than ideal:

alternator > van wiring > engine battery > relay > charger > house
battery (located under bench seat).

The weakness is the van wiring. With a heavy load placed on the engine
battery, there are a couple problems:

The first is that the wiring isn't hefty enough to carry that much
current without losing some voltage, so the engine battery never gets a
full charge.

I found the second problem when poking around in the connector box
located in the engine compartment on the firewall forward of the engine
on the driver's side.

Bentley 97.56 shows a pair of 12-gauge wires coming off the alternator's
B+ terminal and going to the plus connection** in that box. Then a
single 8 gauge wire carries the current to the starter, where a 2 gauge
wire brings the charging current to the engine battery.

When I opened the box I saw that the last inch or so of the wire pair
had darkened insulation, and the connector used to connect them to the
plus connection was nearly black.

Clearly the heavy load I'd been placing on the wiring had overheated
that connection, increasing its resistance and further reducing the
charge voltage on the engine battery.

Though the heavy current draw through that route will no longer exist,
because I am adding a new 0-gauge wire from the alternator directly to a
new relocated charging circuit right at the new house battery, I still
bypassed that weak link by installing a new wire directly from the
alternator to the starter using a pre-made cable from Van-Cafe (search
for VC.ALTCABLE***), leaving the old wiring in place for whatever the
heck else gets powered off Connection 21.

I hope this will encourage owners of the 1.9l van to at least take a
look inside the connector box to make sure their charge wire isn't
showing signs of heating. The box snaps open, it's easy.

=============
* Powerstream PST-BC1212-15 <http://www.powerstream.com/DCC.htm>

** Connection 21, seen on Track 22 on 97.56 and mislabeled as a "ground
connection" on Bentley 97.54.

*** Or make your own. I didn't measure the length of the Van-Cafe part
before installing it, but you'll want a large-gauge cable with a pair of
5/16'' ring lugs on the ends.

--
Jack "Rocket j Squirrel" Elliott
1984 Westfalia, auto trans,
Bend, Ore.