Date: Sat, 27 Jul 2013 08:36:16 -0400
Reply-To: Larry Alofs <lalofs@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Larry Alofs <lalofs@GMAIL.COM>
Subject: Re: Radiator fan resistor
In-Reply-To: <CANEuo0hAvrBoGB=pmwn-g2h5cJVDzLoG1o+pcPOHT=XSM=_R+Q@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
I believe that the failure mode goes something like this:
The "ceramic" coating deteriorates and cracks due to age and extreme
thermal cycling. The coating at such a flaw no longer provides as much
heat sinking as it should and moisture is admitted. This causes
accelerated corrosion and the wire is eventually eaten thru.
When the resistor failed on my '91 GL, I thought that I could borrow one
from one of the two late model vans that I have "awaiting restoration". I
found that both of those resistors had already failed in the very same area.
In the archives I found some posts from someone (Eric?) saying that these
could be repaired by soldering a piece of copper wire across the break. By
carefully picking away at the cracked coating I located the bad spot,
scraped the ends of the exposed wire, and soldered a patch successfully.
The other important step is to coat the repair and other cracked areas
effectively to seal out water and provide heat sinking. The best coating
that I have found so far is high temperature paint made for BBQ grills and
the like, Rust-Oleum High Heat 1200F. It took at least 6 coats before I
felt it was thick enough. I have been using a such a repaired resistor for
about a year and a half now and it's doing the job.
For many people this may seem to be more trouble than it's worth, but
I'm a "thrifty" Dutchman and on a fixed retiree's income.
Regardless, I think some preventative maintainence might be wise for anyone
with AC. Check the resistor for cracks and apply additional coating as
needed.
Stay cool,
Larry A.
On Sat, Jul 27, 2013 at 7:37 AM, kenneth wilford (Van-Again) <
kenwilfy@comcast.net> wrote:
> Dennis,
>
> We have them. Not sure why you didn't contact us about it.
>
> I think the failure on these is related to air flow (or lack thereof) more
> than anything. They aren't in a good air stream like all of the other
> resistors that VW used in their fan systems. Usually they mount them right
> in the air stream and they last forever. This one is mounted behind the
> headlight so you get extra heat from that. If you aren't going down the
> road there is no air flow at all. So here is the worst case for these,
> idling, with the AC on, and the headlights on. Some people run their
> headlights in the day time when on trips. That would make it even worse in
> the summer. If we could move the location to behind the fan, above the
> spare tire area, I think you would find that they would live a lot longer.
>
> Ken Wilford
> John 3:16
> www.vanagain.com
>
>
>
> On Fri, Jul 26, 2013 at 10:56 PM, Dennis Haynes <d23haynes57@hotmail.com
> >wrote:
>
> > Last week the fan resistor in Fun Bus failed on the way to see my son in
> > the
> > hospital. As many of us know the Vanagon resistor is no longer available
> > and
> > we have been using the Eurovan version part # 701959263D. The dealer list
> > for this is now $103 so I tried to order from a number of list vendors
> with
> > no luck. So reluctantly I ordered one form the dealer. I picked it up
> today
> > and guess what! It has been redesigned. It will still fit in the original
> > bracket but it is oval in shape and the resistance wire is considerably
> > larger. It appears they finally realized the original design just
> couldn't
> > handle the load. Anyway, it look like it is worth the cost if it reduces
> > the
> > failure rate. Unfortunately for us Vanagon folk we still have to adapt
> the
> > wiring.
> >
> >
> >
> > Dennis
> >
>
>
>
> --
> Thanks,
> Ken Wilford
> John 3:16
> www.vanagain.com
>
|