Date: Thu, 9 Oct 2003 20:02:27 -0800
Reply-To: Jack <john.cook58@VERIZON.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jack <john.cook58@VERIZON.NET>
Subject: Re: Short Fused about plastic fuses
In-Reply-To: <Pine.GSO.4.05.10310092015380.25284-100000@atlas.kennesaw.edu>
Content-type: text/plain; charset=US-ASCII
> 1) A fuse is a fuse is a fuse right??? as long as is the right Amp
For our purposes, you're right. But you'd be amazed at how complicated fuse
design can really be. Ultimately they are compromises.
- One thing to watch out for in older installations. The contacts to the
fuse and the surrounding wire connections must be good and clean. If not,
enough heat can be generated to start melting & charring insulation,
including plastic fuse bodies. This is true anywhere in an electrical
system but is commonly a problem around automotive fuse blocks (the heart of
the electrical system).
[Back when I had a '61 beetle, I eventually ripped out the awful German
fuse system and installed more reliable American fuses & fuse connectors.]
- The worst case condition for a fuse is to have an abnormal load
condition resulting in a current (amps) near the fuse rating; ie, not a full
short, but enough to get the fuse hot yet not hot enough to melt the fusable
metal link and clear the circuit. That's when I agree that ceramic or glass
cartridges are safer than plastic. Actual shorts (load current much higher
than fuse rating) is more likely to cause a fuse to blow fast & cleanly.
- Do NOT increase the rating of a fuse unless you know what you're doing.
If the correct rating is blowing, find out why! You might be making an
existing problem even worse.
- I know that old DC motors can be a problem (e.g, wipers). But that's
getting away from my own expertise. I'll leave that for someone else to
advise on.
- Also, perhaps someone else can help you straighten out your fuse size
situation ala Bentley or whatever. That needs to get done right.
//Jack
On 9 Oct 2003, at 20:41, Jorge Osorio wrote:
> Volks in the past week I've had some troubling experiences with those
> plastic jelly bean fuses. As soon as the weather turns colder, my Westy
> begins to blow fuses like pop-corn (Well, ok I'm exagerating) The one I seem
> to loose the most is the windshield wiper one. Last week to my amaze, my
> wipers stopped working again, and when I looked at the fuse box, the fuse had
> completely burned thru the cover and melted onto the metal prongs!! I was
> lucky perhpas that the cover limited the amount of air for combustion or I
> would've had myself a Roasty Westy. Anyhow, I went to my FLAPS to see If I
> could find more of those suckers and the guy at the counter told me that they
> sold the glass type fuses which are a direct replacement for those "pop-art"
> jelly bean ones. I got one of those miscelaneous packages and tried a
> 16A..puff blown..then a 25A, Works!!
>
> My question/concern is:
>
> 2) I've fooled around so much with the fuses that I'm not even sure I have
> the right ones in the right places. I've checked the Bentley but I'm confused
> cause the Bentley lists more fuses than what I have in my fuse panel, anyone
> knows the right amperage I need to use on each slot??? I'll probably replace
> all the jelly bean ones for glass ones as a "Smokey The Bear" strategy.
>
> As far as the blown fuse experience goes, I'll take the glass ones any
> day, they blow the same way the trees fall in the forest when nobody is
> watching, and best of all no melted plastic to scrape and remove, Yuk!!
>
> Jorge
>
> '85 Westy Wolfsburg
>
> Betsy, a.k.a "Plan B"
