Date: Fri, 19 Sep 1997 06:08:20 -0600
Reply-To: Dave Fain <KC3565L@SPRINTMAIL.COM>
Sender: Vanagon mailing list <Vanagon@Gerry.SDSC.EDU>
From: Dave Fain <KC3565L@SPRINTMAIL.COM>
Subject: Re: Overheating on '84 Vanagon
Content-Type: text/plain; charset=us-ascii
Notice to non-waterboxer owners. You can delete this
one, it's sorta long and doesn't apply to you.
> Got that dreaded call yesterday from my SO... "the bus started
> overheating in traffic, coolant was gushing out the back".
>
> I checked all the archives on the new list server, but only found one
> thread that dealt with a blown fuse, not the wiring of the fan
> switches.
>
> Then I checked the radiator fan, which worked when I applied a hot
> lead. Then I checked the Bentley manual, which shows TWO
> thermo-switches, one for a low speed circuit, one for a high speed. I
> removed the front grill and found ONE thermo switch screwed into the
> radiator, with three wires DANGLING in space (a red/white, a
> red/black, and a red/blue), all with non-factory connectors. The
> red/white comes up from behind the radiator, the red/black and red/blue
> come from four wire to two wire gray connectors. The DPO strikes again!!
>
> I tried several combinations of attaching these wires to the
> thermo-switch, then jumpered the two connections and sometimes the fan
> would come on, other times not, and other times, it would just stay on
> even after removing the jumper!
>
> I cannot for the life of me figure out how they hook up, why there are
> three wires, nor can I find the second thermo-switch that is shown in
> the Bentley wiring diagram.
Paul, my '84 Westfalia has one thermo switch and it is on
the lower left (as viewed from the driver's seat) of the
radiator, not the upper right near the bleeder as shown
in the Bentley manual. If you have the same Bentley
manual that I have, the diagram on pg 97.59 does show
two separate switches for the '84. Mine, however, is
wired as shown on pg 97.66, which is supposed to be for
a '85. The R/W wire supplies power to the switch via
fuse #7. The R/Bk and R/Bl wires feed the low and
high speed windings of the fan motor. My guess is
that VW modified the wiring in late '84, that must
be what we have. No idea why touching the wires
would make your fan come on and stay on, maybe the
relay under the dash is sticking somehow? Does it
do it when the engine is cold or was it already
hot when you tried this?
By the way, I tapped into these wires and installed a
switch on the dash that lets me switch the fan on
manually BEFORE the engine gets hot enough for the
thermo switch to turn it on. Nice for long hills
and when I'm stuck in traffic. I soldered the
connections and covered them with heat shrink tubing.
Here's another tip for Water Boxer owners. When I
first bought mine, the fuse (#7) that feeds the
radiator fan kept blowing, leaving me with no
cooling when the van wasn't moving. What I found
was that water had made its way into the black
plastic sheath around the wires feeding the radiator
thermo switch. Where the 3 wires join the rest of
the wiring harness above the spare tire, the sheath
had been heat welded to the sheath on the rest of the
harness. The heat had apparently damaged the insulation
on some of the wires so, when the harness filled up
with rain water, it created a dead short and blew
the fuse. I slit the sheath from the thermo switch
to the Y where it joins the rest of the harness and
muddy water ran out of it. I let it dry out and replaced
the sheath with zip ties around it. No more problems
with blown fuses!
Hope some of you find this information useful.
Dave
| 
